Gigabyte GA-Z77X-UD5H Restarts instead of Shutdown

I have a Gigabyte GA-Z77X-UD5H and Windows 8 64 bit. The PC has been shutting down fine with an old monitor connected via VGA to a R9 280X GPU. I've now installed a new Viewsonic VP2770 monitor via DVI. When I shut down, the PC nowrestarts instead. Is there a BIOS setting or Windows 8 setting to ensure the PC shuts down correctly?

I have that motherboard. I can't think of anything that a different monitor (or interface) would cause. I'm using the PC with this motherboard right now so I can't look at the BIOS, but check the Power section to see if something is enabled that would cause this.

I have had a problem with the auto start time changing. I have mine set to auto power on at a set time in the morning. It has changed several times on its own to a different (earlier) startup time. I've had to reset it several times. The motherboard has some other problems (no USB 3 and no DVI output from the i7 3770 CPU motherboard DVI port) and I just received an RMA from Gigabyte to return it for warranty repair/replacement.