Problem with object position

Hi,

I tried to instantiate objects from C++ code.
For do this, I used the "PhysicsShape" object, and my attempt has been successful.

But now I've two big problems:

1) When trying to set position, the engine accept this position, but immediately move my object in a new very different position.

2) When exit mission, I encounter the following error:
"Phys"XWorld::_destroy() - Some actors and/or joints were not released"

Someone can help me?

Thanks!