could just be a crappy card. Chaintech sucks IMO, and I base this off of experience. I had an FX 5700...it overheated and died within 2 months (no I didn't overclock, didn't know how at the time) so I got it RMA'd, and about mmmm 6 months later that card died....never again will I buy a chaintech product.
Basically what I'm saying is, you might have to look into getting it RMA'd