I built a system last night that is constantly locking up on me. It's a p3-750, not overclocked, 128MB RAM, Geforce video, SMC NIC. After about 3 minutes of use, freeze. I can reboot using ctrl-alt-del, so it's not a total freeze. One type of lock up is when I drag an item to the trash can. The icons are shadowed like when they are being dropped in, but the process doesn't complete. Any ideas?