You might need to play with it a bit, testing different flags. Maybe not using POLYGON with c_move, but setting all of the moving entities with a collision box to POLYGON, and using OBB for the rest.

I hope you find a way to achieve what you are trying to do, and hopefully things will change in the future to where we won't need to use this work-around. I remember you posting something in the bug hunt forum about this issue last October HPW, I didn't realize it was you until I checked my old messages.

Well, keep testing and good luck.