diff --git a/extras/audio plugin host/src/host/InternalFilters.cpp b/extras/audio plugin host/src/host/InternalFilters.cpp
index 097e5debe1..4aa17e582d 100644
--- a/extras/audio plugin host/src/host/InternalFilters.cpp	
+++ b/extras/audio plugin host/src/host/InternalFilters.cpp	
@@ -98,7 +98,7 @@ class AudioInputDeviceFilter     : public InternalFilterBase
 public:
     AudioInputDeviceFilter (const int numChannels)
     {
-        numOutputChannels = numChannels;
+        setPlayConfigDetails (0, numChannels, getSampleRate(), getBlockSize());
     }
 
     ~AudioInputDeviceFilter() {}
@@ -115,7 +115,7 @@ public:
         AudioIODevice* const dev = getAudioDevice();
 
         if (dev != 0)
-            numOutputChannels = dev->getActiveInputChannels().countNumberOfSetBits();
+            setPlayConfigDetails (0, dev->getActiveInputChannels().countNumberOfSetBits(), getSampleRate(), getBlockSize());
     }
 
     void JUCE_CALLTYPE prepareToPlay (double /*sampleRate*/, int /*estimatedSamplesPerBlock*/)
@@ -178,7 +178,7 @@ class AudioOutputDeviceFilter     : public InternalFilterBase
 public:
     AudioOutputDeviceFilter (const int numChannels)
     {
-        numInputChannels = numChannels;
+        setPlayConfigDetails (numChannels, 0, getSampleRate(), getBlockSize());
     }
 
     ~AudioOutputDeviceFilter() {}
@@ -195,7 +195,7 @@ public:
         AudioIODevice* const dev = getAudioDevice();
 
         if (dev != 0)
-            numInputChannels = dev->getActiveOutputChannels().countNumberOfSetBits();
+            setPlayConfigDetails (dev->getActiveOutputChannels().countNumberOfSetBits(), 0, getSampleRate(), getBlockSize());
     }
 
     void JUCE_CALLTYPE prepareToPlay (double /*sampleRate*/, int /*estimatedSamplesPerBlock*/)
diff --git a/extras/audio plugin host/src/plugins/juce_AudioPluginInstance.cpp b/extras/audio plugin host/src/plugins/juce_AudioPluginInstance.cpp
index 82c8e99750..4c7b1a9988 100644
--- a/extras/audio plugin host/src/plugins/juce_AudioPluginInstance.cpp	
+++ b/extras/audio plugin host/src/plugins/juce_AudioPluginInstance.cpp	
@@ -44,7 +44,7 @@ AudioPluginInstance::AudioPluginInstance()
 {
     internalAsyncUpdater = new InternalAsyncUpdater (*this);
 
-    initialiseInternal (this);
+    setHostCallbacks (this);
 }
 
 AudioPluginInstance::~AudioPluginInstance()
@@ -127,7 +127,7 @@ void JUCE_CALLTYPE AudioPluginInstance::informHostOfParameterChange (int index,
     queueChangeMessage (index);
 }
 
-void JUCE_CALLTYPE AudioPluginInstance::updateHostDisplay()
+void JUCE_CALLTYPE AudioPluginInstance::informHostOfStateChange()
 {
     queueChangeMessage (-1);
 }
diff --git a/extras/audio plugin host/src/plugins/juce_AudioPluginInstance.h b/extras/audio plugin host/src/plugins/juce_AudioPluginInstance.h
index 1223ecf2f4..bea6247872 100644
--- a/extras/audio plugin host/src/plugins/juce_AudioPluginInstance.h	
+++ b/extras/audio plugin host/src/plugins/juce_AudioPluginInstance.h	
@@ -67,7 +67,7 @@ public:
     @see AudioFilterBase, AudioPluginFormat
 */
 class AudioPluginInstance   : public AudioFilterBase,
-                              private AudioFilterBase::FilterNativeCallbacks
+                              private AudioFilterBase::HostCallbacks
 {
 public:
     //==============================================================================
@@ -168,7 +168,7 @@ protected:
 
     bool JUCE_CALLTYPE getCurrentPositionInfo (AudioFilterBase::CurrentPositionInfo& info);
     void JUCE_CALLTYPE informHostOfParameterChange (int index, float newValue);
-    void JUCE_CALLTYPE updateHostDisplay();
+    void JUCE_CALLTYPE informHostOfStateChange();
 };
 
 
diff --git a/extras/audio plugin host/src/plugins/vst/juce_VSTPluginInstance.cpp b/extras/audio plugin host/src/plugins/vst/juce_VSTPluginInstance.cpp
index c58c8011bb..3560ac47e8 100644
--- a/extras/audio plugin host/src/plugins/vst/juce_VSTPluginInstance.cpp	
+++ b/extras/audio plugin host/src/plugins/vst/juce_VSTPluginInstance.cpp	
@@ -640,22 +640,22 @@ void VSTPluginInstance::initialise()
     dispatch (effIdentify, 0, 0, 0, 0);
 
     {
-        char buffer [kVstMaxEffectNameLen + 8];
+        char buffer [256];
         zerostruct (buffer);
         dispatch (effGetEffectName, 0, 0, buffer, 0);
 
-        name = String (buffer);
-        if (name.trim().isEmpty())
+        name = String (buffer).trim();
+        if (name.isEmpty())
             name = module->pluginName;
     }
 
-    dispatch (effSetSampleRate, 0, 0, 0, (float) sampleRate);
-    dispatch (effSetBlockSize, 0, jmax (16, blockSize), 0, 0);
+    dispatch (effSetSampleRate, 0, 0, 0, (float) getSampleRate());
+    dispatch (effSetBlockSize, 0, jmax (32, getBlockSize()), 0, 0);
 
     dispatch (effOpen, 0, 0, 0, 0);
 
-    numOutputChannels = effect->numOutputs;
-    numInputChannels = effect->numInputs;
+    setPlayConfigDetails (effect->numInputs, effect->numOutputs, 
+                          getSampleRate(), getBlockSize());
 
     if (getNumPrograms() > 1)
         setCurrentProgram (0);
@@ -676,11 +676,13 @@ void VSTPluginInstance::initialise()
 
 
 //==============================================================================
-void JUCE_CALLTYPE VSTPluginInstance::prepareToPlay (double sampleRate_, int samplesPerBlockExpected)
+void JUCE_CALLTYPE VSTPluginInstance::prepareToPlay (double sampleRate_, 
+                                                     int samplesPerBlockExpected)
 {
-    sampleRate = sampleRate_;
-    blockSize = samplesPerBlockExpected;
-    midiCollector.reset (sampleRate);
+    setPlayConfigDetails (effect->numInputs, effect->numOutputs, 
+                          sampleRate_, samplesPerBlockExpected);
+
+    midiCollector.reset (sampleRate_);
 
     juce_free (channels);
     channels = (float**) juce_calloc (sizeof (float*) * jmax (16, getNumOutputChannels() + 2, getNumInputChannels() + 2));
@@ -688,7 +690,7 @@ void JUCE_CALLTYPE VSTPluginInstance::prepareToPlay (double sampleRate_, int sam
     vstHostTime.tempo = 120.0;
     vstHostTime.timeSigNumerator = 4;
     vstHostTime.timeSigDenominator = 4;
-    vstHostTime.sampleRate = sampleRate;
+    vstHostTime.sampleRate = sampleRate_;
     vstHostTime.samplePos = 0;
     vstHostTime.flags = kVstNanosValid;  /*| kVstTransportPlaying | kVstTempoValid | kVstTimeSigValid*/;
 
@@ -706,10 +708,10 @@ void JUCE_CALLTYPE VSTPluginInstance::prepareToPlay (double sampleRate_, int sam
 
         incomingMidi.clear();
 
-        dispatch (effSetSampleRate, 0, 0, 0, (float) sampleRate);
-        dispatch (effSetBlockSize, 0, jmax (16, blockSize), 0, 0);
+        dispatch (effSetSampleRate, 0, 0, 0, (float) sampleRate_);
+        dispatch (effSetBlockSize, 0, jmax (16, samplesPerBlockExpected), 0, 0);
 
-        tempBuffer.setSize (effect->numOutputs, blockSize);
+        tempBuffer.setSize (effect->numOutputs, samplesPerBlockExpected);
 
         if (! isPowerOn)
             setPower (true);
@@ -734,7 +736,7 @@ void JUCE_CALLTYPE VSTPluginInstance::releaseResources()
         setPower (false);
     }
 
-    midiCollector.reset (sampleRate);
+    midiCollector.reset (getSampleRate());
     tempBuffer.setSize (1, 1);
     incomingMidi.clear();
 
@@ -1274,7 +1276,7 @@ private:
         checkPluginWindowSize();
 #endif
 
-        startTimer (18 + juce::Random::getSystemRandom().nextInt (5));
+        startTimer (18 + JUCE_NAMESPACE::Random::getSystemRandom().nextInt (5));
         repaint();
     }
 
@@ -1417,8 +1419,7 @@ AudioFilterEditor* JUCE_CALLTYPE VSTPluginInstance::createEditor()
 void VSTPluginInstance::handleAsyncUpdate()
 {
     // indicates that something about the plugin has changed..
-    if (callbacks != 0)
-        callbacks->updateHostDisplay();
+    updateHostDisplay();
 }
 
 //==============================================================================
@@ -1547,7 +1548,7 @@ void VSTPluginInstance::setParamsInProgramBlock (fxProgram* const prog) throw()
         prog->params[i] = swapFloat (getParameter (i));
 }
 
-bool VSTPluginInstance::saveToFXBFile (juce::MemoryBlock& dest, bool isFXB, int maxSizeMB)
+bool VSTPluginInstance::saveToFXBFile (JUCE_NAMESPACE::MemoryBlock& dest, bool isFXB, int maxSizeMB)
 {
     const int numPrograms = getNumPrograms();
     const int numParams = getNumParameters();
@@ -1556,7 +1557,7 @@ bool VSTPluginInstance::saveToFXBFile (juce::MemoryBlock& dest, bool isFXB, int
     {
         if (isFXB)
         {
-            juce::MemoryBlock chunk;
+            JUCE_NAMESPACE::MemoryBlock chunk;
             getChunkData (chunk, false, maxSizeMB);
 
             const int totalLen = sizeof (fxChunkSet) + chunk.getSize() - 8;
@@ -1576,7 +1577,7 @@ bool VSTPluginInstance::saveToFXBFile (juce::MemoryBlock& dest, bool isFXB, int
         }
         else
         {
-            juce::MemoryBlock chunk;
+            JUCE_NAMESPACE::MemoryBlock chunk;
             getChunkData (chunk, true, maxSizeMB);
 
             const int totalLen = sizeof (fxProgramSet) + chunk.getSize() - 8;
@@ -1614,7 +1615,7 @@ bool VSTPluginInstance::saveToFXBFile (juce::MemoryBlock& dest, bool isFXB, int
             set->numPrograms = swap (numPrograms);
 
             const int oldProgram = getCurrentProgram();
-            juce::MemoryBlock oldSettings;
+            JUCE_NAMESPACE::MemoryBlock oldSettings;
             createTempParameterStore (oldSettings);
 
             setParamsInProgramBlock ((fxProgram*) (((char*) (set->programs)) + oldProgram * progLen));
@@ -1643,7 +1644,7 @@ bool VSTPluginInstance::saveToFXBFile (juce::MemoryBlock& dest, bool isFXB, int
     return true;
 }
 
-void VSTPluginInstance::getChunkData (juce::MemoryBlock& mb, bool isPreset, int maxSizeMB) const
+void VSTPluginInstance::getChunkData (JUCE_NAMESPACE::MemoryBlock& mb, bool isPreset, int maxSizeMB) const
 {
     if (usesChunks())
     {
@@ -1856,10 +1857,10 @@ VstIntPtr VSTPluginInstance::handleCallback (VstInt32 opcode, VstInt32 index, Vs
         return 1;
 
     case audioMasterGetSampleRate:
-        return (VstIntPtr) sampleRate;
+        return (VstIntPtr) getSampleRate();
 
     case audioMasterGetBlockSize:
-        return (VstIntPtr) blockSize;
+        return (VstIntPtr) getBlockSize();
 
     case audioMasterWantMidi:
         wantsMidiMessages = true;
@@ -2142,7 +2143,7 @@ bool VSTPluginInstance::isParameterAutomatable (int index) const
     return false;
 }
 
-void VSTPluginInstance::createTempParameterStore (juce::MemoryBlock& dest)
+void VSTPluginInstance::createTempParameterStore (JUCE_NAMESPACE::MemoryBlock& dest)
 {
     dest.setSize (64 + 4 * getNumParameters());
     dest.fillWith (0);
@@ -2154,7 +2155,7 @@ void VSTPluginInstance::createTempParameterStore (juce::MemoryBlock& dest)
         p[i] = getParameter(i);
 }
 
-void VSTPluginInstance::restoreFromTempParameterStore (const juce::MemoryBlock& m)
+void VSTPluginInstance::restoreFromTempParameterStore (const JUCE_NAMESPACE::MemoryBlock& m)
 {
     changeProgramName (getCurrentProgram(), (const char*) m);
 
@@ -2226,7 +2227,7 @@ void VSTPluginInstance::updateStoredProgramNames()
         if (dispatch (effGetProgramNameIndexed, 0, -1, nm, 0) == 0)
         {
             const int oldProgram = getCurrentProgram();
-            juce::MemoryBlock oldSettings;
+            JUCE_NAMESPACE::MemoryBlock oldSettings;
             createTempParameterStore (oldSettings);
 
             for (int i = 0; i < getNumPrograms(); ++i)
@@ -2345,11 +2346,6 @@ bool VSTPluginInstance::canMono() const throw()
     return effect != 0 && (effect->flags & effFlagsCanMono) != 0;
 }
 
-bool VSTPluginInstance::canReplace() const throw()
-{
-    return effect != 0 && (effect->flags & effFlagsCanReplacing) != 0;
-}
-
 bool VSTPluginInstance::isOffline() const throw()
 {
     return dispatch (effCanDo, 0, 0, (void*) "offline", 0) > 0;
diff --git a/extras/audio plugin host/src/plugins/vst/juce_VSTPluginInstance.h b/extras/audio plugin host/src/plugins/vst/juce_VSTPluginInstance.h
index c3f2d17280..d61bcf41aa 100644
--- a/extras/audio plugin host/src/plugins/vst/juce_VSTPluginInstance.h	
+++ b/extras/audio plugin host/src/plugins/vst/juce_VSTPluginInstance.h	
@@ -172,7 +172,6 @@ private:
     int getVersionNumber() const throw();
     bool hasEditor() const throw();
     bool canMono() const throw();
-    bool canReplace() const throw();
     bool isOffline() const throw();
     void setPower (const bool on);
 
diff --git a/extras/audio plugins/wrapper/formats/AudioUnit/juce_AudioUnitWrapper.cpp b/extras/audio plugins/wrapper/formats/AudioUnit/juce_AudioUnitWrapper.cpp
index 0dbaf92035..378f3dea35 100644
--- a/extras/audio plugins/wrapper/formats/AudioUnit/juce_AudioUnitWrapper.cpp	
+++ b/extras/audio plugins/wrapper/formats/AudioUnit/juce_AudioUnitWrapper.cpp	
@@ -50,7 +50,7 @@ END_JUCE_NAMESPACE
 
 //==============================================================================
 class JuceAU   : public AUMIDIEffectBase,
-                 public AudioFilterBase::FilterNativeCallbacks
+                 public AudioFilterBase::HostCallbacks
 {
 public:
     //==============================================================================
@@ -75,7 +75,7 @@ public:
         }
 
         juceFilter = createPluginFilter();
-        juceFilter->initialiseInternal (this);
+        juceFilter->setHostCallbacks (this);
 
         jassert (juceFilter != 0);
         Globals()->UseIndexedParameters (juceFilter->getNumParameters());
@@ -396,7 +396,7 @@ public:
         }
     }
 
-    void updateHostDisplay()
+    void informHostOfStateChange()
     {
         // xxx is there an AU equivalent?
     }
@@ -433,10 +433,12 @@ public:
     {
         if (juceFilter != 0)
         {
-            juceFilter->numInputChannels = GetInput(0)->GetStreamFormat().mChannelsPerFrame;
-            juceFilter->numOutputChannels = GetOutput(0)->GetStreamFormat().mChannelsPerFrame;
+            juceFilter->setPlayConfigDetails (GetInput(0)->GetStreamFormat().mChannelsPerFrame,
+                                              GetOutput(0)->GetStreamFormat().mChannelsPerFrame,
+                                              GetSampleRate(),
+                                              GetMaxFramesPerSlice());
 
-            bufferSpace.setSize (juceFilter->numInputChannels + juceFilter->numOutputChannels,
+            bufferSpace.setSize (juceFilter->getNumInputChannels() + juceFilter->getNumOutputChannels(),
                                  GetMaxFramesPerSlice() + 32);
 
             juceFilter->prepareToPlay (GetSampleRate(),
@@ -445,8 +447,8 @@ public:
             midiEvents.clear();
 
             juce_free (channels);
-            channels = (float**) juce_calloc (sizeof (float*) * jmax (juceFilter->numInputChannels,
-                                                                      juceFilter->numOutputChannels) + 4);
+            channels = (float**) juce_calloc (sizeof (float*) * jmax (juceFilter->getNumInputChannels(),
+                                                                      juceFilter->getNumOutputChannels()) + 4);
 
             prepared = true;
         }
@@ -474,8 +476,8 @@ public:
             int numOutChans = 0;
             int nextSpareBufferChan = 0;
             bool needToReinterleave = false;
-            const int numIn = juceFilter->numInputChannels;
-            const int numOut = juceFilter->numOutputChannels;
+            const int numIn = juceFilter->getNumInputChannels();
+            const int numOut = juceFilter->getNumOutputChannels();
 
             unsigned int i;
             for (i = 0; i < outBuffer.mNumberBuffers; ++i)
@@ -547,7 +549,7 @@ public:
 
                 const ScopedLock sl (juceFilter->getCallbackLock());
 
-                if (juceFilter->suspended)
+                if (juceFilter->isSuspended())
                 {
                     for (int i = 0; i < numOut; ++i)
                         zeromem (channels [i], sizeof (float) * numSamples);
diff --git a/extras/audio plugins/wrapper/formats/RTAS/juce_RTASWrapper.cpp b/extras/audio plugins/wrapper/formats/RTAS/juce_RTASWrapper.cpp
index f07d4f7802..39bd0a9045 100644
--- a/extras/audio plugins/wrapper/formats/RTAS/juce_RTASWrapper.cpp	
+++ b/extras/audio plugins/wrapper/formats/RTAS/juce_RTASWrapper.cpp	
@@ -114,7 +114,7 @@ static long floatToLong (const float n) throw()
 //==============================================================================
 class JucePlugInProcess  : public CEffectProcessMIDI,
                            public CEffectProcessRTAS,
-                           public AudioFilterBase::FilterNativeCallbacks,
+                           public AudioFilterBase::HostCallbacks,
                            public AsyncUpdater
 {
 public:
@@ -537,8 +537,8 @@ protected:
         SFicPlugInStemFormats stems;
         GetProcessType()->GetStemFormats (&stems);
 
-        juceFilter->numInputChannels = fNumInputs;
-        juceFilter->numOutputChannels = fNumOutputs;
+        juceFilter->setPlayConfigDetails (fNumInputs, fNumOutputs, 
+                                          juceFilter->getSampleRate(), juceFilter->getBlockSize());
 
         AddControl (new CPluginControl_OnOff ('bypa', "Master Bypass\nMastrByp\nMByp\nByp", false, true));
         DefineMasterBypassControlIndex (bypassControlIndex);
@@ -572,7 +572,7 @@ protected:
 
         midiTransport = new CEffectMIDITransport (&mMIDIWorld);
 
-        juceFilter->initialiseInternal (this);
+        juceFilter->setHostCallbacks (this);
     }
 
     void handleAsyncUpdate()
@@ -586,6 +586,9 @@ protected:
             channels = (float**) juce_calloc (sizeof (float*) * jmax (juceFilter->getNumInputChannels(), 
                                                                       juceFilter->getNumOutputChannels()));
 
+            juceFilter->setPlayConfigDetails (fNumInputs, fNumOutputs, 
+                                              sampleRate, mRTGlobals->mHWBufferSizeInSamples);
+
             juceFilter->prepareToPlay (sampleRate,
                                        mRTGlobals->mHWBufferSizeInSamples);
 
@@ -640,11 +643,11 @@ protected:
         {
             const ScopedLock sl (juceFilter->getCallbackLock());
 
-            const int numIn = juceFilter->numInputChannels;
-            const int numOut = juceFilter->numOutputChannels;
+            const int numIn = juceFilter->getNumInputChannels();
+            const int numOut = juceFilter->getNumOutputChannels();
             const int totalChans = jmax (numIn, numOut);
 
-            if (juceFilter->suspended)
+            if (juceFilter->isSuspended())
             {
                 for (int i = 0; i < numOut; ++i)
                     zeromem (outputs [i], sizeof (float) * numSamples);
@@ -845,7 +848,7 @@ protected:
         SetControlValue (index + 2, floatToLong (newValue));
     }
 
-    void JUCE_CALLTYPE updateHostDisplay()
+    void JUCE_CALLTYPE informHostOfStateChange()
     {
         // xxx is there an RTAS equivalent?
     }
diff --git a/extras/audio plugins/wrapper/formats/Standalone/juce_AudioFilterStreamer.cpp b/extras/audio plugins/wrapper/formats/Standalone/juce_AudioFilterStreamer.cpp
index e1a1c84963..4673c284f2 100644
--- a/extras/audio plugins/wrapper/formats/Standalone/juce_AudioFilterStreamer.cpp	
+++ b/extras/audio plugins/wrapper/formats/Standalone/juce_AudioFilterStreamer.cpp	
@@ -40,10 +40,9 @@ AudioFilterStreamer::AudioFilterStreamer (AudioFilterBase& filterToUse)
       sampleRate (0),
       emptyBuffer (1, 32)
 {
-    filter.numInputChannels = JucePlugin_MaxNumInputChannels;
-    filter.numOutputChannels = JucePlugin_MaxNumOutputChannels;
+    filter.setPlayConfigDetails (JucePlugin_MaxNumInputChannels, JucePlugin_MaxNumOutputChannels, 0, 0);
 
-    filter.initialiseInternal (this);
+    filter.setHostCallbacks (this);
 }
 
 AudioFilterStreamer::~AudioFilterStreamer()
@@ -85,7 +84,7 @@ void AudioFilterStreamer::audioDeviceIOCallback (const float** inputChannelData,
     {
         const ScopedLock sl (filter.getCallbackLock());
 
-        if (filter.suspended)
+        if (filter.isSuspended())
         {
             output.clear();
         }
@@ -144,7 +143,7 @@ void AudioFilterStreamer::informHostOfParameterChange (int index, float newValue
 }
 
 
-void JUCE_CALLTYPE AudioFilterStreamer::updateHostDisplay()
+void JUCE_CALLTYPE AudioFilterStreamer::informHostOfStateChange()
 {
 }
 
diff --git a/extras/audio plugins/wrapper/formats/Standalone/juce_AudioFilterStreamer.h b/extras/audio plugins/wrapper/formats/Standalone/juce_AudioFilterStreamer.h
index a4ff7aacff..988a71ec1f 100644
--- a/extras/audio plugins/wrapper/formats/Standalone/juce_AudioFilterStreamer.h	
+++ b/extras/audio plugins/wrapper/formats/Standalone/juce_AudioFilterStreamer.h	
@@ -51,7 +51,7 @@
 */
 class AudioFilterStreamer   : public AudioIODeviceCallback,
                               public MidiInputCallback,
-                              public AudioFilterBase::FilterNativeCallbacks
+                              public AudioFilterBase::HostCallbacks
 {
 public:
     //==============================================================================
@@ -73,7 +73,7 @@ public:
 
     bool JUCE_CALLTYPE getCurrentPositionInfo (AudioFilterBase::CurrentPositionInfo& info);
     void JUCE_CALLTYPE informHostOfParameterChange (int index, float newValue);
-    void JUCE_CALLTYPE updateHostDisplay();
+    void JUCE_CALLTYPE informHostOfStateChange();
 
     juce_UseDebuggingNewOperator
 
diff --git a/extras/audio plugins/wrapper/formats/VST/juce_VstWrapper.cpp b/extras/audio plugins/wrapper/formats/VST/juce_VstWrapper.cpp
index b9f658d1d0..24e6947085 100644
--- a/extras/audio plugins/wrapper/formats/VST/juce_VstWrapper.cpp	
+++ b/extras/audio plugins/wrapper/formats/VST/juce_VstWrapper.cpp	
@@ -299,7 +299,7 @@ static VoidArray activePlugins;
 */
 class JuceVSTWrapper  : public AudioEffectX,
                         private Timer,
-                        public AudioFilterBase::FilterNativeCallbacks
+                        public AudioFilterBase::HostCallbacks
 {
 public:
     //==============================================================================
@@ -310,10 +310,11 @@ public:
                        filter_->getNumParameters()),
          filter (filter_)
     {
-        filter->numInputChannels = JucePlugin_MaxNumInputChannels;
-        filter->numOutputChannels = JucePlugin_MaxNumOutputChannels;
+        filter->setPlayConfigDetails (JucePlugin_MaxNumInputChannels,
+                                      JucePlugin_MaxNumOutputChannels,
+                                      0, 0);
 
-        filter_->initialiseInternal (this);
+        filter_->setHostCallbacks (this);
 
         editorComp = 0;
         outgoingEvents = 0;
@@ -336,8 +337,8 @@ public:
         wantEvents();
 #endif
 
-        setNumInputs (filter->numInputChannels);
-        setNumOutputs (filter->numOutputChannels);
+        setNumInputs (filter->getNumInputChannels());
+        setNumOutputs (filter->getNumOutputChannels());
 
         canProcessReplacing (true);
 
@@ -531,16 +532,19 @@ public:
 
     void process (float** inputs, float** outputs, VstInt32 numSamples)
     {
-        AudioSampleBuffer temp (filter->numInputChannels, numSamples);
+        const int numIn = filter->getNumInputChannels();
+        const int numOut = filter->getNumOutputChannels();
+
+        AudioSampleBuffer temp (numIn, numSamples);
         int i;
-        for (i = filter->numInputChannels; --i >= 0;)
+        for (i = numIn; --i >= 0;)
             memcpy (temp.getSampleData (i), outputs[i], sizeof (float) * numSamples);
 
         processReplacing (inputs, outputs, numSamples);
 
-        AudioSampleBuffer dest (outputs, filter->numOutputChannels, numSamples);
+        AudioSampleBuffer dest (outputs, numOut, numSamples);
 
-        for (i = jmin (filter->numOutputChannels, filter->numInputChannels); --i >= 0;)
+        for (i = jmin (numIn, numOut); --i >= 0;)
             dest.addFrom (i, 0, temp, i, 0, numSamples);
     }
 
@@ -564,11 +568,11 @@ public:
         {
             const ScopedLock sl (filter->getCallbackLock());
 
-            const int numIn = filter->numInputChannels;
-            const int numOut = filter->numOutputChannels;
+            const int numIn = filter->getNumInputChannels();
+            const int numOut = filter->getNumOutputChannels();
             const int totalChans = jmax (numIn, numOut);
 
-            if (filter->suspended)
+            if (filter->isSuspended())
             {
                 for (int i = 0; i < numOut; ++i)
                     zeromem (outputs [i], sizeof (float) * numSamples);
@@ -650,16 +654,19 @@ public:
         juce_free (channels);
         channels = (float**) juce_calloc (sizeof (float*) * jmax (filter->getNumInputChannels(), filter->getNumOutputChannels()));
 
-        filter->sampleRate = getSampleRate();
+        double rate = getSampleRate();
+        jassert (rate > 0);
+        if (rate <= 0.0)
+            rate = 44100.0;
 
-        jassert (filter->sampleRate > 0);
-        if (filter->sampleRate <= 0)
-            filter->sampleRate = 44100.0;
+        const int blockSize = getBlockSize();
+        jassert (blockSize > 0);
 
-        filter->blockSize = getBlockSize();
-        jassert (filter->blockSize > 0);
+        filter->setPlayConfigDetails (JucePlugin_MaxNumInputChannels,
+                                      JucePlugin_MaxNumOutputChannels,
+                                      rate, blockSize);
 
-        filter->prepareToPlay (filter->sampleRate, filter->blockSize);
+        filter->prepareToPlay (rate, blockSize);
         midiEvents.clear();
 
         AudioEffectX::resume();
@@ -807,7 +814,7 @@ public:
         setParameterAutomated (index, newValue);
     }
 
-    void JUCE_CALLTYPE updateHostDisplay()
+    void JUCE_CALLTYPE informHostOfStateChange()
     {
         updateDisplay();
     }
diff --git a/extras/audio plugins/wrapper/juce_AudioFilterBase.cpp b/extras/audio plugins/wrapper/juce_AudioFilterBase.cpp
index 390cdc5215..c5cae7b753 100644
--- a/extras/audio plugins/wrapper/juce_AudioFilterBase.cpp	
+++ b/extras/audio plugins/wrapper/juce_AudioFilterBase.cpp	
@@ -34,13 +34,13 @@
 
 //==============================================================================
 AudioFilterBase::AudioFilterBase()
-    : sampleRate (0),
+    : callbacks (0),
+      activeEditor (0),
+      sampleRate (0),
       blockSize (0),
       numInputChannels (0),
       numOutputChannels (0),
-      callbacks (0),
-      suspended (false),
-      activeEditor (0)
+      suspended (false)
 {
 }
 
@@ -51,11 +51,22 @@ AudioFilterBase::~AudioFilterBase()
     jassert (activeEditor == 0);
 }
 
-void AudioFilterBase::initialiseInternal (FilterNativeCallbacks* const callbacks_)
+void AudioFilterBase::setHostCallbacks (HostCallbacks* const callbacks_)
 {
     callbacks = callbacks_;
 }
 
+void AudioFilterBase::setPlayConfigDetails (const int numIns, 
+                                            const int numOuts, 
+                                            const double sampleRate_,
+                                            const int blockSize_) throw()
+{
+    numInputChannels = numIns;
+    numOutputChannels = numOuts;
+    sampleRate = sampleRate_;
+    blockSize = blockSize_;
+}
+
 void AudioFilterBase::setParameterNotifyingHost (const int parameterIndex,
                                                  const float newValue)
 {
@@ -70,7 +81,7 @@ void AudioFilterBase::setParameterNotifyingHost (const int parameterIndex,
 void JUCE_CALLTYPE AudioFilterBase::updateHostDisplay()
 {
     if (callbacks != 0)
-        callbacks->updateHostDisplay();
+        callbacks->informHostOfStateChange();
 }
 
 bool AudioFilterBase::isParameterAutomatable (int /*index*/) const
diff --git a/extras/audio plugins/wrapper/juce_AudioFilterBase.h b/extras/audio plugins/wrapper/juce_AudioFilterBase.h
index 2c7757b9f0..806b9cd802 100644
--- a/extras/audio plugins/wrapper/juce_AudioFilterBase.h	
+++ b/extras/audio plugins/wrapper/juce_AudioFilterBase.h	
@@ -40,6 +40,7 @@
 #include "juce_AudioFilterEditor.h"
 #undef MemoryBlock
 
+
 //==============================================================================
 /**
     Base class for audio filters or plugins written using JUCE.
@@ -313,6 +314,11 @@ public:
     */
     void JUCE_CALLTYPE suspendProcessing (const bool shouldBeSuspended);
 
+    /** Returns true if processing is currently suspended.
+        @see suspendProcessing
+    */
+    bool JUCE_CALLTYPE isSuspended() const throw()                                  { return suspended; }
+
     //==============================================================================
     /** Creates the filter's UI.
 
@@ -493,16 +499,17 @@ public:
 
     //==============================================================================
     /** @internal */
-    class FilterNativeCallbacks
+    class HostCallbacks
     {
     public:
-        virtual ~FilterNativeCallbacks() {}
+        virtual ~HostCallbacks() {}
+
         virtual bool JUCE_CALLTYPE getCurrentPositionInfo (CurrentPositionInfo& info) = 0;
         virtual void JUCE_CALLTYPE informHostOfParameterChange (int index, float newValue) = 0;
 
         /** Callback to indicate that something (other than a parameter) has changed in the 
             filter, such as its current program, parameter list, etc. */
-        virtual void JUCE_CALLTYPE updateHostDisplay() = 0;
+        virtual void JUCE_CALLTYPE informHostOfStateChange() = 0;
     };
 
 
@@ -512,10 +519,17 @@ public:
     */
     void JUCE_CALLTYPE editorBeingDeleted (AudioFilterEditor* const editor);
 
-    /** Not for public use - this is called by the wrapper code to initialised the
+    /** Not for public use - this is called by the wrapper code to initialise the
         filter.
     */
-    void JUCE_CALLTYPE initialiseInternal (FilterNativeCallbacks* const);
+    void JUCE_CALLTYPE setHostCallbacks (HostCallbacks* const);
+
+    /** Not for public use - this is called by the wrapper code to initialise the
+        filter.
+    */
+    void setPlayConfigDetails (const int numIns, const int numOuts, 
+                               const double sampleRate,
+                               const int blockSize) throw();
 
     //==============================================================================
     juce_UseDebuggingNewOperator
@@ -542,24 +556,14 @@ protected:
                                                        const int sizeInBytes);
 
     /** @internal */
-    double sampleRate;
-    /** @internal */
-    int blockSize, numInputChannels, numOutputChannels;
-    /** @internal */
-    FilterNativeCallbacks* callbacks;
+    HostCallbacks* callbacks;
 
 private:
-    friend class JuceVSTWrapper;
-    friend class JuceAU;
-    friend class JuceAUView;
-    friend class AudioFilterEditor;
-    friend class AudioFilterStreamer;
-    friend class JucePlugInProcess;
-
-    CriticalSection callbackLock;
-    bool suspended;
-
     AudioFilterEditor* activeEditor;
+    double sampleRate;
+    int blockSize, numInputChannels, numOutputChannels;
+    bool suspended;
+    CriticalSection callbackLock;
 };
 
 //==============================================================================
diff --git a/extras/audio plugins/wrapper/juce_AudioFilterEditor.cpp b/extras/audio plugins/wrapper/juce_AudioFilterEditor.cpp
index 23a3f52c5d..d09151ced5 100644
--- a/extras/audio plugins/wrapper/juce_AudioFilterEditor.cpp	
+++ b/extras/audio plugins/wrapper/juce_AudioFilterEditor.cpp	
@@ -45,5 +45,5 @@ AudioFilterEditor::~AudioFilterEditor()
 {
     // if this fails, then the wrapper hasn't called editorBeingDeleted() on the
     // filter for some reason..
-    jassert (ownerFilter->activeEditor != this);
+    jassert (ownerFilter->getActiveEditor() != this);
 }