When I first built my computer it was fine. Nothing wrong. But now it has become unstable. I have an AMD 2100+, Asus A7N8X Deluxe mobo, crucial 512 pc2700 ram, ati sapphire radeon 9500 nonpro, 450watt power supply. I have the AMD oc'ed to 2700. Temp is staying at low 30C 32-36C. What could make it unstable? Thanks