I have had this x800pro for two weeks now and I first installed it in my Nforce2 mobo with an Athlon 2500+ and it ran just fine and everything was stable. I got an Athlon 64 3200+ with a Soyo Board K8USA with the 8151 chipset by Ali (AMD) and I try to run Halo and Far Cry and they crash every time. The system will not run them, the video card isn't overclocked since I did the switch and I did two fresh reinstalls of windows, once with xp pro and again with windows 2000. I've tried Cat 4.4-4.7beta and Omegas 4.6 along with updating the chipset drivers and sound card drivers. I have three sticks of ram and have swapped all of them in and out running one at a time and still get the same crash. I worried that my video card may be the problem but I can play City of Heroes fine along with running 3dmark2k1, 2k3, and the ATi X800 demos. I ran prime95 for a couple of hours while running the Ruby demo at the same time and got 0 errors and the ruby demo ran smooth. I don't under stand...Prime 95 is set to use 512mb of system memory leaving me with 512mb extra for windows and everything else. Everything runs but Halo and Far Cry...any advice...can someone please help???