Custom PC won't turn OFF

[afireinside7710]

I have a custom PC that runs beautifully! Fast and cheap, running Vista. But I have one odd problem with it. When I go to shut down the PC (either by start -> shut down, putting it to sleep, or by the power button) it never fully shuts off. Instead it seems to restart and goes through boot up like i had just turned it back on or hit restart instead.
Here is a list of hardware (from memory since I am not home):
Motherboard: Gigabyte GA-M61SME-S2
Processor: AMD Athlon X2 5000+
RAM: <unknown manufacturer and model ATM> 2x2GB
HD: Western Digital 320GB
PSU: Thermaltake TR2 430W Watt ATX

Like I said, when booted the PC has no problems what so ever and runs with ease. I have built 3 PCs in the past so I do know what I am doing when it comes to the hardware, software, and BIOS. Any ideas?

 

[Indigo]

Vista is known for this little...quirk. Make sure you're running all the latest patches and drivers via Windows Update or for the parts in the system. Alternatively, I haven't had this issue on 7, and there's really no reason to not be running 7 these days...