DG33TL and Power Down Issue

[DPGX]

I assembled the system last night, however upon shutting down vista at the end of the night (with a clean install) the system does not power down. It shuts off all Windows Services and proceeds to a black screen (which cannot be woken up from this state), but does not power down the system completely. I can power down the system by holding the power button at this point but am unsure what the issue is?

I have clean installed the O/S, and have the latest firmware for my mainboard, any suggestions?

Thanks!