I recently upgraded my video card to an ATI Radeon x800, and for the most part, it works rather well. However, whenever I try to restart, the computer powers up normally while the monitor stays dormant. I've tried just turning the power off then on again, but the same thing just happens. After I let it sit for an hour or two usually it will work again, but it's really aggravating after a newly installed program wants you to restart your computer and this happens. Could it be overheating? It runs at about 50-55 C. Any help would be appreciated. Thanks!