Sorry by my poor English. I am spaniard and I have a 8800gt xxx 512 graphic card and also have this problem. After 5 minutes more or less my computer freeze and not respond (control+alt+supr) Keyboard, mouse, nothing respond and the only "solution" is reboot the computer.
My computer:
c2d 6400+4 gigas RAM+8800gt xxx 512
I hope next patch will solve this problem.