I just volt modded my evga 7900gt CO SC. GPU at 1.49v, mem at 2.32v. Right now the card is running at 500/1500, this card is suppose to run at 550/1580. When I bump the ram up to 1580, my computer freezes and the display starts going in and out and I end up havin to reboot. The card runs fine normally and the voltages are stable but I just cant seem to overclock it just a little bit, let alone get it to run at its stock speeds. Any ideas? Im using rivatuner to OC btw.