ok. i hear that there is issues with the game and the 8800 series. there is a beta version of the nVidia driver. I don't know the exact version. (i don't have the card.) get it and everything should be fine.
I'm having the same problem on my card :S It runs the Stress Test fine but if you go into playing the actual game it freezes after a couple of mins. I'll get the Beta drivers when I get home.
