I found a solution on my pc, let me decide with everybody, hope, some of u find it useful.
My rig is x2 4400+ @2.53, 7950GT.
On the nvidia control panel I switched extension limit: ON, Threaded optimisation OFF, and the game ran pretty much smooth on both best @ 1024x768. I trieds to switch one of the core off and on and found it better with both of them running. (latest nvidia driver)
Good luck