diff --git a/c++/patchcanvas/canvasbox.cpp b/c++/patchcanvas/canvasbox.cpp
index 6e51a08..00430f9 100644
--- a/c++/patchcanvas/canvasbox.cpp
+++ b/c++/patchcanvas/canvasbox.cpp
@@ -136,6 +136,12 @@ void CanvasBox::setGroupName(QString group_name)
     updatePositions();
 }
 
+void CanvasBox::setShadowOpacity(float opacity)
+{
+    if (shadow)
+        shadow->setOpacity(opacity);
+}
+
 CanvasPort* CanvasBox::addPortFromGroup(int port_id, QString port_name, PortMode port_mode, PortType port_type)
 {
     if (m_port_list_ids.count() == 0)
diff --git a/c++/patchcanvas/canvasbox.h b/c++/patchcanvas/canvasbox.h
index c6cf6c2..5feca1c 100644
--- a/c++/patchcanvas/canvasbox.h
+++ b/c++/patchcanvas/canvasbox.h
@@ -54,6 +54,8 @@ public:
     void setSplit(bool split, PortMode mode=PORT_MODE_NULL);
     void setGroupName(QString group_name);
 
+    void setShadowOpacity(float opacity);
+
     CanvasPort* addPortFromGroup(int port_id, QString port_name, PortMode port_mode, PortType port_type);
     void removePortFromGroup(int port_id);
     void addLineFromGroup(AbstractCanvasLine* line, int connection_id);
diff --git a/c++/patchcanvas/canvasboxshadow.cpp b/c++/patchcanvas/canvasboxshadow.cpp
index 667703e..ffe2546 100644
--- a/c++/patchcanvas/canvasboxshadow.cpp
+++ b/c++/patchcanvas/canvasboxshadow.cpp
@@ -36,6 +36,13 @@ void CanvasBoxShadow::setFakeParent(CanvasBox* fakeParent)
     m_fakeParent = fakeParent;
 }
 
+void CanvasBoxShadow::setOpacity(float opacity)
+{
+        QColor color(canvas.theme->box_shadow);
+        color.setAlphaF(opacity);
+        setColor(color);
+}
+
 void CanvasBoxShadow::draw(QPainter* painter)
 {
     if (m_fakeParent)
diff --git a/c++/patchcanvas/canvasboxshadow.h b/c++/patchcanvas/canvasboxshadow.h
index 8fed7a5..41d2072 100644
--- a/c++/patchcanvas/canvasboxshadow.h
+++ b/c++/patchcanvas/canvasboxshadow.h
@@ -31,6 +31,7 @@ class CanvasBoxShadow : public QGraphicsDropShadowEffect
 public:
     CanvasBoxShadow(QObject* parent);
     void setFakeParent(CanvasBox* fakeParent);
+    void setOpacity(float opacity);
 
 protected:
     virtual void draw(QPainter* painter);
diff --git a/c++/patchcanvas/canvasfadeanimation.cpp b/c++/patchcanvas/canvasfadeanimation.cpp
index e298cf5..e0c3077 100644
--- a/c++/patchcanvas/canvasfadeanimation.cpp
+++ b/c++/patchcanvas/canvasfadeanimation.cpp
@@ -17,7 +17,7 @@
 
 #include "canvasfadeanimation.h"
 
-#include <QGraphicsItem>
+#include "canvasbox.h"
 
 START_NAMESPACE_PATCHCANVAS
 
@@ -63,6 +63,9 @@ void CanvasFadeAnimation::updateCurrentTime(int time)
       value = 1.0-(float(time)/m_duration);
 
     m_item->setOpacity(value);
+
+    if (m_item->type() == CanvasBoxType)
+        ((CanvasBox*)m_item)->setShadowOpacity(value);
 }
 
 void CanvasFadeAnimation::updateState(QAbstractAnimation::State /*newState*/, QAbstractAnimation::State /*oldState*/)
diff --git a/c++/patchcanvas/canvastestapp.cpp b/c++/patchcanvas/canvastestapp.cpp
index 85806d1..db98fd6 100644
--- a/c++/patchcanvas/canvastestapp.cpp
+++ b/c++/patchcanvas/canvastestapp.cpp
@@ -156,7 +156,7 @@ CanvasTestApp::CanvasTestApp(QWidget *parent) :
     options.auto_hide_groups = false;
     options.use_bezier_lines = true;
     options.antialiasing = PatchCanvas::ANTIALIASING_SMALL;
-    options.eyecandy = PatchCanvas::EYECANDY_FULL;
+    options.eyecandy = PatchCanvas::EYECANDY_SMALL;
     options.theme_name = PatchCanvas::getDefaultThemeName();
 
     PatchCanvas::features_t features;
diff --git a/c++/patchcanvas/patchcanvas-api.h b/c++/patchcanvas/patchcanvas-api.h
index 5607ca7..e21da1f 100644
--- a/c++/patchcanvas/patchcanvas-api.h
+++ b/c++/patchcanvas/patchcanvas-api.h
@@ -128,6 +128,7 @@ void connectPorts(int connection_id, int port_out_id, int port_in_id);
 void disconnectPorts(int connection_id);
 
 void arrange();
+void updateZValues();
 
 END_NAMESPACE_PATCHCANVAS
 
diff --git a/c++/patchcanvas/patchcanvas.cpp b/c++/patchcanvas/patchcanvas.cpp
index 22e2e66..5a2a6c9 100644
--- a/c++/patchcanvas/patchcanvas.cpp
+++ b/c++/patchcanvas/patchcanvas.cpp
@@ -305,6 +305,15 @@ void addGroup(int group_id, QString group_name, SplitOption split, Icon icon)
     if (canvas.debug)
         qDebug("PatchCanvas::addGroup(%i, %s, %s, %s)", group_id, group_name.toUtf8().constData(), split2str(split), icon2str(icon));
 
+    foreach (const group_dict_t& group, canvas.group_list)
+    {
+        if (group.group_id == group_id)
+        {
+            qWarning("PatchCanvas::addGroup(%i, %s, %s, %s) - group already exists", group_id, group_name.toUtf8().constData(), split2str(split), icon2str(icon));
+            return;
+        }
+    }
+
     if (split == SPLIT_UNDEF && features.handle_group_pos)
         split = static_cast<SplitOption>(canvas.settings->value(QString("CanvasPositions/%1_SPLIT").arg(group_name), split).toInt());
 
@@ -716,6 +725,15 @@ void addPort(int group_id, int port_id, QString port_name, PortMode port_mode, P
     if (canvas.debug)
         qDebug("PatchCanvas::addPort(%i, %i, %s, %s, %s)", group_id, port_id, port_name.toUtf8().constData(), port_mode2str(port_mode), port_type2str(port_type));
 
+    foreach (const port_dict_t& port, canvas.port_list)
+    {
+        if (port.group_id == group_id and port.port_id == port_id)
+        {
+            qWarning("PatchCanvas::addPort(%i, %i, %s, %s, %s) - port already exists" , group_id, port_id, port_name.toUtf8().constData(), port_mode2str(port_mode), port_type2str(port_type));
+            return;
+        }
+    }
+
     CanvasBox* box_widget = 0;
     CanvasPort* port_widget = 0;
 
@@ -938,6 +956,21 @@ void arrange()
         qDebug("PatchCanvas::Arrange()");
 }
 
+void updateZValues()
+{
+    if (canvas.debug)
+        qDebug("PatchCanvas::updateZValues()");
+
+
+    foreach (const group_dict_t& group, canvas.group_list)
+    {
+        group.widgets[0]->resetLinesZValue();
+
+        if (group.split and group.widgets[1])
+            group.widgets[1]->resetLinesZValue();
+    }
+}
+
 /* Extra Internal functions */
 
 QString CanvasGetGroupName(int group_id)