Assuming you've done all of the regular stuff . . . we might just want to chalk this up to the mystery of nforce chipsets . . . 'cause that's the only thing that a lot of these weird problems have in common (and it's across the board with Epox, Asus and other motherboards as you've probably seen on lots of tech support sights). So you've done all the regular stuff such as clear CMOS overnight (not just 10 seconds), isolated motherboard from chasis, one stick of ram that you know to be good, bare essentials installed (floppy, one SATA HD, graphics card, CDROM, RAM), tested PSU for correct voltages, newest BIOS flash, etc? I'm tapped out as far as solutions, otherwise. It's the nforce chipset curse, I'd reckon. Please keep us informed if you ever find a cure, OK?