I upgraded from a nvidia 5200 to an ati radeon 9550. I experienced no crashes with my old video card, but the new one doesn't just freeze the computer, it restarts it. the screen will go black and the monitor click off. I've even tried it on a different motherboard(not for very long) and it worked fine. I have a chaintech mpm800-3 with a socket 478 celeron 2.93 ghz. i also receive a no conductor 80 cable installed line when booting but that's doesn't seem to cause any problems. any ideas?