MSI P55-GD55 won't enter Setup unless I click "Restart" instead of "Shut down" (?!?!)

[Ichinisan]

After numerous attempts, I realized I was completely unable to enter CMOS Setup.

I tried pacing myself as I tapped the "Del" key repeatedly. I tried waiting for the "Initializing USB controllers" message to disappear. I tried furiously tapping Del. I tried tapping it alternately with the Pause/Break key. Nothing worked. There wasn't even a message indicating "Press Del to enter setup" -- which I've seen many times before.

Finally, I clicked "Restart" instead of "Shut Down" and the message was there! I pressed "Del" and got to the BIOS CMOS Setup.

What's up with that?

 

[Ichinisan]

I changed Quick Boot to "Disabled" and it shows a "Press <ESC> to boot...." screen every time with a 10-second countdown. I recall that disabling Quick Boot on older motherboards always did some kind of memory test during POST. This didn't seem to be doing anything except counting down 10 seconds. Still, it started allowing me to enter CMOS Setup every time. I disabled Quick Boot and it still works every time.

Very strange.