Physics error...program crashes

I am using t3d 1.2 created a terrain and when I switched camera to player the program crashes. Console log shows the following error about 50 times...

PhysX Error:
D:\sw\physx\PhysXSDK\2.8.4\trunk\SDKs\Physics\src\NpPhysicsSDK.cpp(870) : PhysicsSDK::releaseHeightField: instances of this heightfield still exist!

I have searched and looked for info on this...apologies if I have missed it.