JD, I just can't get used to this new nomenclature. Wikipedia says that the old IDE was retroactively renamed PATA. That's nice -- I'm sure they went back and changed all of the written literature, but they didn't rewrite my brain! Also, the Asus manuals still refer to an IDE connector and it says "IDE" on the silkscreen. But, I will try.
Oz, your P5Q Pro motherboard has 3 drive controllers. The ICH10 Southbridge for SATA 1-6, a PATA-only controller, and a second SATA-only controller for connectors 7 & 8. That's a lot of storage capability! The P5E3 Deluxe board that I worked on recently had only 2 controllers, but it would flash a message "No any drive detected" from the PATA controller which had nothing connected. I suppose that you are lucky if you only see one such message since you probably have 2 controllers with no drives attached.