Weird, I'm writing this on my PC with the knackered 9800 in
It works with the case off and the PC lying on its side, but if I put the case back on and stand the PC upright it's a no go, so heat......
Not likely because with the case ON theres a fan that blows hot air directly onto the GFX card???
PSU? again not very likely it a fairly new Thermaltake 480W and all I have in my PC is a soundcard 2 CD and 2 HD and 5 fans.
Anyone got any ideas??