wow that is one of the craziest things ive heard in a long time. First thing to do to eliminate the possibilty of it being your proc switch the card out with another one. If its your proc then you know what to do. If its your vid card then do the following:
a: Revert back to the original 9800pro bios
b: Replace cooler/ thermal compound
c: Try a differnt power line from the
psu and unplug all fans lights un-needed items
d: try a differnt monitor lol