You could underclock it and see if that works. This is a crappy solution to your problem.
Also, you could try anaftermarket cooler if the card is overheathing. I think that's what VPU recovery is for.
My buddy had to send his card back to the MFG (He had the same issue with a 9800XT). This was just a month ago, so even if your card is old, you should still be able to gget some service.
One other thing, On my X850xt, it was a hot running card untill I figured out that the fan on the card was running at 10% untill temps got to 80 degrees C. I downloaded ATI tool and set up the fan speed properly. Now i get about 62 degrees C under full load. Perhaps your fan speed is slow....