diff --git a/macosx/coreaudio/JackCoreAudioDriver.cpp b/macosx/coreaudio/JackCoreAudioDriver.cpp
index 26d86988..3b02ae9c 100644
--- a/macosx/coreaudio/JackCoreAudioDriver.cpp
+++ b/macosx/coreaudio/JackCoreAudioDriver.cpp
@@ -216,8 +216,8 @@ OSStatus JackCoreAudioDriver::Render(void *inRefCon,
 
 int JackCoreAudioDriver::Read()
 {
-    AudioUnitRender(fAUHAL, fActionFags, fCurrentTime, 1, fEngineControl->fBufferSize, fJackInputData);
-    return 0;
+    OSStatus err = AudioUnitRender(fAUHAL, fActionFags, fCurrentTime, 1, fEngineControl->fBufferSize, fJackInputData);
+    return (err == noErr) ? 0 : -1;
 }
 
 int JackCoreAudioDriver::Write()
diff --git a/posix/JackCompilerDeps_os.h b/posix/JackCompilerDeps_os.h
index 767674e1..83afb8e9 100644
--- a/posix/JackCompilerDeps_os.h
+++ b/posix/JackCompilerDeps_os.h
@@ -48,7 +48,7 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
             #define SERVER_EXPORT __attribute__((visibility("default")))
         #endif
     #else
-        #define SERVER_EXPORT
+        #define SERVER_EXPORT __attribute__((visibility("hidden")))
     #endif
 #else
     #define MEM_ALIGN(x,y) x
diff --git a/solaris/oss/JackBoomerDriver.cpp b/solaris/oss/JackBoomerDriver.cpp
index f10b2e89..fc054541 100644
--- a/solaris/oss/JackBoomerDriver.cpp
+++ b/solaris/oss/JackBoomerDriver.cpp
@@ -634,6 +634,7 @@ bool JackBoomerDriver::JackBoomerDriverInput::Init()
     return true;
 }
 
+// TODO : better error handling
 bool JackBoomerDriver::JackBoomerDriverInput::Execute()
 {
   
@@ -721,6 +722,7 @@ bool JackBoomerDriver::JackBoomerDriverOutput::Init()
     return true;
 }
 
+// TODO : better error handling
 bool JackBoomerDriver::JackBoomerDriverOutput::Execute()
 {
     memset(fDriver->fOutputBuffer, 0, fDriver->fOutputBufferSize);
diff --git a/solaris/oss/JackBoomerDriver.h b/solaris/oss/JackBoomerDriver.h
index 61fc5c50..c98e28a3 100644
--- a/solaris/oss/JackBoomerDriver.h
+++ b/solaris/oss/JackBoomerDriver.h
@@ -152,10 +152,7 @@ class JackBoomerDriver : public JackAudioDriver
         }
 
         int SetBufferSize(jack_nframes_t buffer_size);
-        
-        bool Init();
-        bool Execute();
-
+  
 };
 
 } // end of namespace
diff --git a/solaris/oss/JackOSSDriver.cpp b/solaris/oss/JackOSSDriver.cpp
index 7890f6ae..3b66740a 100644
--- a/solaris/oss/JackOSSDriver.cpp
+++ b/solaris/oss/JackOSSDriver.cpp
@@ -707,7 +707,7 @@ int JackOSSDriver::ProcessSync()
     // Read input buffers for the current cycle
     if (Read() < 0) { 
         jack_error("ProcessSync: read error, skip cycle");
-        return 0;   // Skip cycle, but continue processing...
+        return 0;   // Non fatal error here, skip cycle, but continue processing...
     }
 
     if (fIsMaster) {
@@ -719,7 +719,7 @@ int JackOSSDriver::ProcessSync()
     // Write output buffers for the current cycle
     if (Write() < 0) { 
         jack_error("JackAudioDriver::ProcessSync: write error, skip cycle");
-        return 0;   // Skip cycle, but continue processing...
+        return 0;   // Non fatal error here, skip cycle, but continue processing...
     }
     
     return 0;