Get one of Russ's 300W power supplies. It cured my mystery reboots. My power supply was a marginal 225W with a small fan.
www.compucheap.com
Dual 300a/450
Tyan Tiger 100
Adaptec SCSCI
Umax scanner (SCSI)
Zip drive (internal SCSI)
Plextor 820 CD-R (SCSI)
Creative Labs 4x DVD drive
Quantum 10.4GB (5400 rpm)
IBM 30GB (GXP, 7200 rpm)
SB-Live
ASUS V7100 Geforce MX (newest addition)
Netgear ethernet
internal DSL modem (not here yet, waiting semi-patiently)
Way too much for a crappy 225W PS.
Plus, it has two large fans and dropped my case temp by 5 degrees F