Installed 512 MB DDR400 few days back. My Mobo is Asus A7N266-VM (nForce 1), so now my PC has two memory banks, one 256 MB DDR266 and 512 MB DDR400. My mobo officially supports only DDR266 or below. Since installing this new RAM, my PC has got restarted by itself 2-3 times? What could the problem? RAM? What is the solution?