I've not had personal experience with your model mobo, but after looking at ASUS's site on the P5Q, I see there are several SATA ports with 2 unique ones (orange & white). I'm not sure but I'd check your manual to confirm if your primary hard drive needs to be in either the orange or white port ... or one of the maroon ones. There's a reason for the colors ... usually to indicate ports for RAID. Then I'd boot into BIOS and ensure the SATA settings are what's necessary for booting/recognizing a hard drive.
Failing that, do you have a spare non-7200.11 SATA drive to see if it can be recognized? There might be a problem with .11 drives (BIOS update related). I'd check on ASUS's site for a BIOS update for your board ... especially if this is a new build. Typically boards don't come with the latest BIOS updates.