So, I built my computer. Shuttle AN35 ULTRA board w/nvidia ULTRA 400(400) chipset. OS System 512x2 mB DDR400 PC3200 RAM AMD XP 2600+ Nvidia FX5900 Win XP I have the most recent mobo, sound, directx, and video drivers. Anytime I play any 3d game (Homeworld 2, Empires, C&C Generals, etc) it'll crash to desktop within 30 minutes, max. Generals will crash in about 5. There are no other problems other then this, it runs smooth. I don't know what the problem is. Please help.