Im hoping this is actually a software problem rather than hardware but it might be due to a recent power supply I installed in my computer. The new power supply is a Thermatake TR2-430w.
Problem: When I use start menu, turn off computer, turn off, my computer goes through the normal shutdown prociedure then powers off for aprox 1.5 seconds then reboots as if it had just been turned on.
Computer Reboots after "Shutdown" 
Linear Mode
