had the x800 pro non vivo for about 6 months maybe more. Everytime i enable the ati over drive it puts white lines across the screen . I had the ati over drive turned on for about 5 months untill this happened, it sometimes shuts pc off . Is there a problem with these cards over heating. I used ati tool to turn the fan up to 100% but its noisey and turned it down again . i did a scan for atifacts with ati tool, and the temp went up to about 80 deg .So i quickly turned the fan to 100% to cool it down. surly it should not get that hot. please help