I got a 9700 pro refurb from retek, took off the shim etc etc to keep the heat down and all was well for two weeks. Then today I started to get some weird blocks and lines on the screen in windows and half life too. Took off the heatsink again and reseated it with some more thermal paste and the problem was still there. Checked the fan was working and noticed that the card was not even hot, so I dont think overheating is an issue. So in the end I tried uninstalling drivers and reinstalling them which for now seems to have solved the problem. Do you guys think this sounds like a driver issue?? I am not sure but I hope I find out for sure before the warranty is up.