GPU probs

well i just got a new GTX275 but for some reason my computer keeps lockign up while folding. things i know are its not heat never gets above 60ºC, not power had 2x4870 in it which folded fine, drivers tried 186.18 and 182.50 so far both have the same prob and the OS is only about 3 weeks old

Perhaps a slightly dislodged SATA plug? If it is, you'll probably see some disk errors appear in the event log.

i think i may have found my prob i pulled the video card out and took off the heatsink and found that the VRM's were not making good contact with the heat sink so i pulled the thermal pads off and put a some AS5 on the VRM's and a thin small strip of aluminum on top of that which was big enough to make contact with the heat sink and so far it has been running the OCCT GPU test for 20 mins and no lockups and before i could only run it about 3 mins before it locked up on me