Computer wont stay shutdown

After building my new computer I only have one issue. It wont stay shutdown...

I do the shutdown and everything works fine, computer turns off, all the led's and fans go out. Then 2 seconds later it starts right back up!

I have windows vista home premium 32bit.

My computer Specs are:
PC Power & Cooling Silencer 610 PSU
Gigabyte P35-DS3R Motherboard
Intel e4300 overclocked to 2.7ghz (9x300) CPU
3gb OCZ Gold (2x1gb, 2x512mb) RAM
EVGA 8600gts 256mb Video Card
Western Digital WD1600AAJS 160gb SATA Hard Drive
2 IDE DVD- Burners

I tried googling for answers but only found a few things for xp and windows 98, I tried the fix for XP recomended, disabling restart on errors, but that didnt work.

You are not actually shutting down but instead going into a power savings mode at some level. First, check your BIOS and disable your power savings at the BIOS level. If that doesn't work (or you can't as a limitation of the BIOS), then look at the settings under your control panel.

I have tried using the power button, i changed it's function to shutdown.

I usually shut down from the start menu (kind of ironic you have to go to start to shutdown now that I think about it) and that doesn't solve it either.

I will check the bios again when I get home. I believe I disabled all the power saving already.

The computer completes the windows "shuting down" screens, the monitor looses signal, all the system fans cold cathode lights and leds go off. Everything is quiet for a second then it reboots. It's does just like a restart.