I've had to quit using Quad processors with the GV800 and 8.3.1 (XP sp3). Random problems with two different motherboards but the reoccuring one was upon some boots, all live video would have black screens if there was a video signal present. Also, periodically the Bandwidth program would fail. All solved by changing nothing other than putting in a Dual Core E8500 inplace of the Quads. Has anyone else seen this?