diff --git a/examples/Importers/ImportURDFDemo/UrdfParser.cpp b/examples/Importers/ImportURDFDemo/UrdfParser.cpp
index 2ec443db2..cf5b9c626 100644
--- a/examples/Importers/ImportURDFDemo/UrdfParser.cpp
+++ b/examples/Importers/ImportURDFDemo/UrdfParser.cpp
@@ -620,6 +620,15 @@ bool UrdfParser::parseVisual(UrdfModel& model, UrdfVisual& visual, TiXmlElement*
               if (parseMaterial(visual.m_geometry.m_localMaterial, mat,logger))
               {
                   UrdfMaterial* matPtr = new UrdfMaterial(visual.m_geometry.m_localMaterial);
+				  
+				  UrdfMaterial** oldMatPtrPtr = model.m_materials[matPtr->m_name.c_str()];
+				  if (oldMatPtrPtr)
+				  {
+					  UrdfMaterial* oldMatPtr = *oldMatPtrPtr;
+					  model.m_materials.remove(matPtr->m_name.c_str());
+					  if (oldMatPtr)
+						  delete oldMatPtr;
+				  }
                   model.m_materials.insert(matPtr->m_name.c_str(),matPtr);
                   visual.m_geometry.m_hasLocalMaterial = true;
               }
diff --git a/examples/pybullet/pybullet.c b/examples/pybullet/pybullet.c
index cc9bda8d0..b041f88d8 100644
--- a/examples/pybullet/pybullet.c
+++ b/examples/pybullet/pybullet.c
@@ -1,3 +1,4 @@
+
 #include "../SharedMemory/PhysicsClientC_API.h"
 #include "../SharedMemory/PhysicsDirectC_API.h"
 #include "../SharedMemory/SharedMemoryInProcessPhysicsC_API.h"
@@ -398,6 +399,22 @@ static PyObject* pybullet_disconnectPhysicsServer(PyObject* self,
 	return Py_None;
 }
 
+
+void b3pybulletExitFunc()
+{
+	int i;
+	for (i=0;i<MAX_PHYSICS_CLIENTS;i++)
+	{
+		if (sPhysicsClients1[i])
+		{
+			b3DisconnectSharedMemory(sPhysicsClients1[i]);
+			sPhysicsClients1[i] = 0;
+			sNumPhysicsClients--;
+		}
+	}
+}
+
+
 static PyObject* pybullet_saveWorld(PyObject* self, PyObject* args, PyObject* keywds)
 {
 	const char* worldFileName = "";
@@ -5453,6 +5470,10 @@ initpybullet(void)
 	Py_INCREF(SpamError);
 	PyModule_AddObject(m, "error", SpamError);
 
+		
+	Py_AtExit( b3pybulletExitFunc );
+	
+
 #ifdef PYBULLET_USE_NUMPY
 	// Initialize numpy array.
 	import_array();
diff --git a/src/Bullet3Common/b3CommandLineArgs.h b/src/Bullet3Common/b3CommandLineArgs.h
index 481f95aaf..38df8e260 100644
--- a/src/Bullet3Common/b3CommandLineArgs.h
+++ b/src/Bullet3Common/b3CommandLineArgs.h
@@ -29,7 +29,7 @@ public:
 	    {
 	        std::string arg = argv[i];
 
-	        if ((arg[0] != '-') || (arg[1] != '-')) {
+			if ((arg.length() < 2) || (arg[0] != '-') || (arg[1] != '-')) {
 	        	continue;
 	        }