diff --git a/OpenSim/Region/Framework/Scenes/SceneObjectPart.cs b/OpenSim/Region/Framework/Scenes/SceneObjectPart.cs
index eb3af42a13..c9ff4f3c6d 100644
--- a/OpenSim/Region/Framework/Scenes/SceneObjectPart.cs
+++ b/OpenSim/Region/Framework/Scenes/SceneObjectPart.cs
@@ -4089,7 +4089,7 @@ namespace OpenSim.Region.Framework.Scenes
             // For now, we use the NINJA naming scheme for identifying joints.
             // In the future, we can support other joint specification schemes such as a 
             // custom checkbox in the viewer GUI.
-            if (ParentGroup.Scene != null && ParentGroup.Scene.PhysicsScene.SupportsNINJAJoints)
+            if (ParentGroup.Scene != null && ParentGroup.Scene.PhysicsScene != null && ParentGroup.Scene.PhysicsScene.SupportsNINJAJoints)
             {
                 return IsHingeJoint() || IsBallJoint();
             }
@@ -4413,7 +4413,8 @@ namespace OpenSim.Region.Framework.Scenes
         public void RemoveFromPhysics()
         {
             ParentGroup.Scene.EventManager.TriggerObjectRemovedFromPhysicalScene(this);
-            ParentGroup.Scene.PhysicsScene.RemovePrim(PhysActor);
+            if (ParentGroup.Scene.PhysicsScene != null)
+                ParentGroup.Scene.PhysicsScene.RemovePrim(PhysActor);
             PhysActor = null;
         }
 
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSAPIXNA.cs b/OpenSim/Region/Physics/BulletSPlugin/BSAPIXNA.cs
index 6db5f5e77d..2a820bee16 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSAPIXNA.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSAPIXNA.cs
@@ -1221,6 +1221,50 @@ private sealed class BulletConstraintXNA : BulletConstraint
         //BSParam.TerrainImplementation = 0;
         world.SetGravity(new IndexedVector3(0,0,p.gravity));
 
+        // Turn off Pooling since globals and pooling are bad for threading.
+        BulletGlobals.VoronoiSimplexSolverPool.SetPoolingEnabled(false);
+        BulletGlobals.SubSimplexConvexCastPool.SetPoolingEnabled(false);
+        BulletGlobals.ManifoldPointPool.SetPoolingEnabled(false);
+        BulletGlobals.CastResultPool.SetPoolingEnabled(false);
+        BulletGlobals.SphereShapePool.SetPoolingEnabled(false);
+        BulletGlobals.DbvtNodePool.SetPoolingEnabled(false);
+        BulletGlobals.SingleRayCallbackPool.SetPoolingEnabled(false);
+        BulletGlobals.SubSimplexClosestResultPool.SetPoolingEnabled(false);
+        BulletGlobals.GjkPairDetectorPool.SetPoolingEnabled(false);
+        BulletGlobals.DbvtTreeColliderPool.SetPoolingEnabled(false);
+        BulletGlobals.SingleSweepCallbackPool.SetPoolingEnabled(false);
+        BulletGlobals.BroadphaseRayTesterPool.SetPoolingEnabled(false);
+        BulletGlobals.ClosestNotMeConvexResultCallbackPool.SetPoolingEnabled(false);
+        BulletGlobals.GjkEpaPenetrationDepthSolverPool.SetPoolingEnabled(false);
+        BulletGlobals.ContinuousConvexCollisionPool.SetPoolingEnabled(false);
+        BulletGlobals.DbvtStackDataBlockPool.SetPoolingEnabled(false);
+
+        BulletGlobals.BoxBoxCollisionAlgorithmPool.SetPoolingEnabled(false);
+        BulletGlobals.CompoundCollisionAlgorithmPool.SetPoolingEnabled(false);
+        BulletGlobals.ConvexConcaveCollisionAlgorithmPool.SetPoolingEnabled(false);
+        BulletGlobals.ConvexConvexAlgorithmPool.SetPoolingEnabled(false);
+        BulletGlobals.ConvexPlaneAlgorithmPool.SetPoolingEnabled(false);
+        BulletGlobals.SphereBoxCollisionAlgorithmPool.SetPoolingEnabled(false);
+        BulletGlobals.SphereSphereCollisionAlgorithmPool.SetPoolingEnabled(false);
+        BulletGlobals.SphereTriangleCollisionAlgorithmPool.SetPoolingEnabled(false);
+        BulletGlobals.GImpactCollisionAlgorithmPool.SetPoolingEnabled(false);
+        BulletGlobals.GjkEpaSolver2MinkowskiDiffPool.SetPoolingEnabled(false);
+        BulletGlobals.PersistentManifoldPool.SetPoolingEnabled(false);
+        BulletGlobals.ManifoldResultPool.SetPoolingEnabled(false);
+        BulletGlobals.GJKPool.SetPoolingEnabled(false);
+        BulletGlobals.GIM_ShapeRetrieverPool.SetPoolingEnabled(false);
+        BulletGlobals.TriangleShapePool.SetPoolingEnabled(false);
+        BulletGlobals.SphereTriangleDetectorPool.SetPoolingEnabled(false);
+        BulletGlobals.CompoundLeafCallbackPool.SetPoolingEnabled(false);
+        BulletGlobals.GjkConvexCastPool.SetPoolingEnabled(false);
+        BulletGlobals.LocalTriangleSphereCastCallbackPool.SetPoolingEnabled(false);
+        BulletGlobals.BridgeTriangleRaycastCallbackPool.SetPoolingEnabled(false);
+        BulletGlobals.BridgeTriangleConcaveRaycastCallbackPool.SetPoolingEnabled(false);
+        BulletGlobals.BridgeTriangleConvexcastCallbackPool.SetPoolingEnabled(false);
+        BulletGlobals.MyNodeOverlapCallbackPool.SetPoolingEnabled(false);
+        BulletGlobals.ClosestRayResultCallbackPool.SetPoolingEnabled(false);
+        BulletGlobals.DebugDrawcallbackPool.SetPoolingEnabled(false);
+
         return world;
     }
     //m_constraint.ptr, ConstraintParams.BT_CONSTRAINT_STOP_CFM, cfm, ConstraintParamAxis.AXIS_ALL
@@ -1914,7 +1958,7 @@ private sealed class BulletConstraintXNA : BulletConstraint
                                                                            heightMap,  scaleFactor,
                                                                            minHeight, maxHeight, upAxis,
                                                                             false);
-        terrainShape.SetMargin(collisionMargin + 0.5f);
+        terrainShape.SetMargin(collisionMargin);
         terrainShape.SetUseDiamondSubdivision(true);
         terrainShape.SetUserPointer(id);
         return new BulletShapeXNA(terrainShape, BSPhysicsShapeType.SHAPE_TERRAIN);
diff --git a/bin/BulletXNA.dll b/bin/BulletXNA.dll
index bfaac4fa6d..b3ddc32297 100644
Binary files a/bin/BulletXNA.dll and b/bin/BulletXNA.dll differ
diff --git a/bin/BulletXNA.pdb b/bin/BulletXNA.pdb
index ecab22fbb5..ed3baaddd7 100644
Binary files a/bin/BulletXNA.pdb and b/bin/BulletXNA.pdb differ