And it will not work in the designated purple Keyboard interface? Your keyboard should have come with that adapter - maybe in a drawer somewhere....
Frys sells them if you don't have one.
Save gas and, while you're there, pick up a cheap keyboard (that you can return) while you are there, and you will have the other piece of the puzzle.
The keyboard will work fine from the P/S2 port, and intermittently when directly plugged into a USB port. However, I prefer to run fewer cables between my desk and my computer, so I usually use a USB hub for my keyboard, mouse, vdieo camera, microphone, micro-usb cable (phone, camera, etc).
No devices work from the USB hub when connected to this motherboard, although it works fine on other computers.
Many USB controllers claim backward compatibility from 2.0 to 1.1, when in fact they are not. If your keyboard or hub is USB 1.1, there is the source of the dysfunction. I have had a couple of hubs that would not work with my upgraded motherboards and now sit useless in the closet.
Note that the blue rear ports are not backward compatible on the P8P67.
Okay, so before you posted that I was on the Asus website and saw that if I upgrade from BIOS 1302 to 1502, one of the fixes has something to do with expanded USB capability, so I thought that might apply to me.
Well, after installing the BIOS update, when Windows 7 boots up it automatically installs some kind of update for the CPU. I know this because it states 'new hardware driver installed Intel i7-200K', or something (it was only up for a moment after the login screen), and then Windows freezes, never to work or boot up again, although I can revert it to a previous successful boot, but then it just installs the 'new hardware' again. I really think there is something wrong with this board.
It well could be the board, but it's starting to sound at least partially like a corrupted BIOS, I suggest you clear CMOS, then try again. If that doesn't work, then it would probably have to be a bad MB; Asus has had quite a few USB errors for the P67.