Overclocking possibly might have to do with it. Was this a problem before you started overclocking? Did you have an ati card before? If you did have an ati card, did you make sure to remove any possible traces with a driver removal program? Those are the only things I can think of right now. A little off topic, but I'm tired of driver issues with nvidia right now. Im going to sell my 6800 gt and get a x800 xt. I never once had any problems with ATI hardware.