NOT WORKING
After 3 days of testing (trying every catalyst driver from 8.7 up to the newest) I've found a solution.
Using the drivers linked below seems to solve the problem wich caused the game engine to stutter or crash, freezing the game but letting you tab back to windows.
http://support.amd.com/us/kbarticles...or3DGames.aspx
I don't know if it has something to do with the latest patch, but now the game runs flawlessly.
So far I've tested the game with dx10 disabled and no stencil shadows, everything got fine.
As soon as I'll try dx10 on I'll give feedback on it.
EDIT:dx10 enabled, stencil shadows on high. Everything is fine but it will need further testing.
Let me know if this solves your problems.