diff --git a/examples/OpenGLWindow/GLInstancingRenderer.cpp b/examples/OpenGLWindow/GLInstancingRenderer.cpp
index 26d765536..1a66c32df 100644
--- a/examples/OpenGLWindow/GLInstancingRenderer.cpp
+++ b/examples/OpenGLWindow/GLInstancingRenderer.cpp
@@ -1618,7 +1618,7 @@ void GLInstancingRenderer::renderScene()
 	{
 
 		renderSceneInternal(B3_CREATE_SHADOWMAP_RENDERMODE);
-		glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT|GL_STENCIL_BUFFER_BIT);
+		
 
 		if (m_planeReflectionShapeIndex>=0)
 		{
diff --git a/examples/OpenGLWindow/Win32OpenGLWindow.cpp b/examples/OpenGLWindow/Win32OpenGLWindow.cpp
index 28eab35cb..aa71750ad 100644
--- a/examples/OpenGLWindow/Win32OpenGLWindow.cpp
+++ b/examples/OpenGLWindow/Win32OpenGLWindow.cpp
@@ -119,9 +119,9 @@ void	Win32OpenGLWindow::closeWindow()
 void	Win32OpenGLWindow::startRendering()
 {
 		pumpMessage();
-		//don't clear all 3 buffers because some AMD drivers are buggy
-		//glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT|GL_STENCIL_BUFFER_BIT);
-		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+		
+		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT|GL_STENCIL_BUFFER_BIT);
+		
 		
 
 		//glCullFace(GL_BACK);
diff --git a/examples/SharedMemory/PhysicsClientSharedMemory.cpp b/examples/SharedMemory/PhysicsClientSharedMemory.cpp
index a9bf810e6..c78eff91c 100644
--- a/examples/SharedMemory/PhysicsClientSharedMemory.cpp
+++ b/examples/SharedMemory/PhysicsClientSharedMemory.cpp
@@ -1,10 +1,10 @@
 #include "PhysicsClientSharedMemory.h"
 #include "PosixSharedMemory.h"
 #include "Win32SharedMemory.h"
-#include "LinearMath/btAlignedObjectArray.h"
-#include "LinearMath/btVector3.h"
+#include "Bullet3Common/b3AlignedObjectArray.h"
+#include "Bullet3Common/b3Vector3.h"
 #include <string.h>
-
+#include "Bullet3Common/b3HashMap.h"
 #include "Bullet3Common/b3Logging.h"
 #include "../Utils/b3ResourcePath.h"
 #include "../../Extras/Serialize/BulletFileLoader/btBulletFile.h"
@@ -19,7 +19,7 @@
 struct BodyJointInfoCache
 {
 	std::string m_baseName;
-	btAlignedObjectArray<b3JointInfo> m_jointInfo;
+	b3AlignedObjectArray<b3JointInfo> m_jointInfo;
 	std::string m_bodyName;
 };
 
@@ -28,32 +28,32 @@ struct PhysicsClientSharedMemoryInternalData {
 	bool	m_ownsSharedMemory;
     SharedMemoryBlock* m_testBlock1;
    
-	btHashMap<btHashInt,BodyJointInfoCache*> m_bodyJointMap;
-	btHashMap<btHashInt,b3UserConstraint> m_userConstraintInfoMap;
+	b3HashMap<b3HashInt,BodyJointInfoCache*> m_bodyJointMap;
+	b3HashMap<b3HashInt,b3UserConstraint> m_userConstraintInfoMap;
 
-    btAlignedObjectArray<TmpFloat3> m_debugLinesFrom;
-    btAlignedObjectArray<TmpFloat3> m_debugLinesTo;
-    btAlignedObjectArray<TmpFloat3> m_debugLinesColor;
+    b3AlignedObjectArray<TmpFloat3> m_debugLinesFrom;
+    b3AlignedObjectArray<TmpFloat3> m_debugLinesTo;
+    b3AlignedObjectArray<TmpFloat3> m_debugLinesColor;
 
 	int m_cachedCameraPixelsWidth;
 	int m_cachedCameraPixelsHeight;
-	btAlignedObjectArray<unsigned char> m_cachedCameraPixelsRGBA;
-	btAlignedObjectArray<float> m_cachedCameraDepthBuffer;
-	btAlignedObjectArray<int> m_cachedSegmentationMaskBuffer;
+	b3AlignedObjectArray<unsigned char> m_cachedCameraPixelsRGBA;
+	b3AlignedObjectArray<float> m_cachedCameraDepthBuffer;
+	b3AlignedObjectArray<int> m_cachedSegmentationMaskBuffer;
 
-    btAlignedObjectArray<b3ContactPointData> m_cachedContactPoints;
-	btAlignedObjectArray<b3OverlappingObject> m_cachedOverlappingObjects;
-	btAlignedObjectArray<b3VisualShapeData> m_cachedVisualShapes;
-	btAlignedObjectArray<b3CollisionShapeData> m_cachedCollisionShapes;
+    b3AlignedObjectArray<b3ContactPointData> m_cachedContactPoints;
+	b3AlignedObjectArray<b3OverlappingObject> m_cachedOverlappingObjects;
+	b3AlignedObjectArray<b3VisualShapeData> m_cachedVisualShapes;
+	b3AlignedObjectArray<b3CollisionShapeData> m_cachedCollisionShapes;
 
-	btAlignedObjectArray<b3VRControllerEvent> m_cachedVREvents;
-	btAlignedObjectArray<b3KeyboardEvent> m_cachedKeyboardEvents;
-	btAlignedObjectArray<b3MouseEvent> m_cachedMouseEvents;
-	btAlignedObjectArray<double> m_cachedMassMatrix;
-	btAlignedObjectArray<b3RayHitInfo>	m_raycastHits;
+	b3AlignedObjectArray<b3VRControllerEvent> m_cachedVREvents;
+	b3AlignedObjectArray<b3KeyboardEvent> m_cachedKeyboardEvents;
+	b3AlignedObjectArray<b3MouseEvent> m_cachedMouseEvents;
+	b3AlignedObjectArray<double> m_cachedMassMatrix;
+	b3AlignedObjectArray<b3RayHitInfo>	m_raycastHits;
 
-    btAlignedObjectArray<int> m_bodyIdsRequestInfo;
-	btAlignedObjectArray<int> m_constraintIdsRequestInfo;
+    b3AlignedObjectArray<int> m_bodyIdsRequestInfo;
+	b3AlignedObjectArray<int> m_constraintIdsRequestInfo;
 
     SharedMemoryStatus m_tempBackupServerStatus;
     
diff --git a/examples/SharedMemory/Win32SharedMemory.cpp b/examples/SharedMemory/Win32SharedMemory.cpp
index 7a2c688ea..4c7e04d6c 100644
--- a/examples/SharedMemory/Win32SharedMemory.cpp
+++ b/examples/SharedMemory/Win32SharedMemory.cpp
@@ -2,7 +2,7 @@
 #include "Win32SharedMemory.h"
 #include "Bullet3Common/b3Logging.h"
 #include "Bullet3Common/b3Scalar.h"
-#include "LinearMath/btAlignedObjectArray.h"
+#include "Bullet3Common/b3AlignedObjectArray.h"
 
 #include <windows.h>
 #include <stdio.h>
@@ -29,7 +29,7 @@ struct Win32SharedMemorySegment
 struct Win32SharedMemoryInteralData
 {
 	
-	btAlignedObjectArray<Win32SharedMemorySegment> m_segments;
+	b3AlignedObjectArray<Win32SharedMemorySegment> m_segments;
 
 	Win32SharedMemoryInteralData()
 	{
diff --git a/examples/pybullet/pybullet.c b/examples/pybullet/pybullet.c
index 4e0785021..1fae95a6d 100644
--- a/examples/pybullet/pybullet.c
+++ b/examples/pybullet/pybullet.c
@@ -937,6 +937,12 @@ static PyObject* pybullet_changeDynamicsInfo(PyObject* self, PyObject* args, PyO
 		return NULL;
 	}
 	
+	if ((contactStiffness>=0 && contactDamping <0)||(contactStiffness<0 && contactDamping >=0))
+	{
+		PyErr_SetString(SpamError, "Both contactStiffness and contactDamping needs to be set together.");
+		return NULL;
+	}
+
 	{
 		b3SharedMemoryCommandHandle command = b3InitChangeDynamicsInfo(sm);
 		b3SharedMemoryStatusHandle statusHandle;
diff --git a/src/Bullet3Common/b3AlignedObjectArray.h b/src/Bullet3Common/b3AlignedObjectArray.h
index 947362d08..ef7101656 100644
--- a/src/Bullet3Common/b3AlignedObjectArray.h
+++ b/src/Bullet3Common/b3AlignedObjectArray.h
@@ -528,6 +528,14 @@ protected:
 		otherArray.copy(0, otherSize, m_data);
 	}
 
+	void removeAtIndex(int index)
+    {
+        if (index<size())
+        {
+            swap( index,size()-1);
+            pop_back();
+        }
+    }
 };
 
 #endif //B3_OBJECT_ARRAY__