Nice, that sounds cool. I was planning on doing what you are about to do, however, heat issues scared me off. I was worried the case wouldn't accommodate the larger gpu, and temps it would throw at it.
either through a temp monitoring tool for instance SpeedFan, or just by touching the heatsinks while under stress and if they are very hot then you know.
Still not working? Have you tried multiple servers, game types, maps, etc? Also have you tried turning the graphics settings down or checking to make sure nothing is overheating?
Holy crap you have a grudge against amd. I search new threads with amd phenom's mentioned, and you're in every single one preaching the gospel of intel and the damnation of amd!