ATI has it's own set of specific problems.
That's why I only buy NVidia cards. I've never had a problem with any NVidia card, but now I know not to upgrade to any GTX560 and newer graphics cards.
I'd get on the NVidia forums and state your problem there. Those guys and NVidia might have an answer for you. Or send in to NVidia Support and where you bought it from and ask about a warranty or replacement.