Ok, a little system info first:

A7V8X-MX motherboard
AMD Duron 1.4 GHZ CPU
250watt power supply
256mb Apacer DDR2100 memory
Western Digital 20gb hard drive
USR internal modem
CD-ROM Drive
Floppy drive

Ok, now that that's out of the way, here's what's going on. When I press the power button to power it up, it comes on for about 2 seconds, then turns off for a second, then powers back on, and will come up ok. Also, when I shut down Windows (WinXP Pro), it goes to the "It's now safe to turn off your machine" screen, but when I press the power button, nothing happens. I have to hold the button for 5 or 6 seconds to get it to turn off. I have the power button set to "Instant Off" in the bios, and the rest are the fail safe settings. Any ideas on what's going on? Thanks