SATA problem

Only one SATA channel activated in BIOS?

Jam it back in, in the dark.

Then check the whole BIOS or get yourself the manual (either in print form or as download from the mainboard vendor).
If the channel is not deactivated in BIOS then it is possible dead.

Also pay attention on BIOS POST if the drive is recognized during this procedure.

There's nowhere I can't reach.

Look inside the menu "integrated peripherals". If there are no options to enable/disable the SATA channels then probably they're both enabled all the time.

Maybe you should pay attention during POST if the SATA channel status is printed to screen. Most of the time the detected devices are shown for a short time. If such a message exists then both devices should show up. If only one device does show up and there are really NO options in BIOS for SATA then I suspect the second channel to be dead.
If the second device shows up then its probably a software problem and you should get something like a Linux live CD (gentoo, knoppix, whatever) to see if the device is detected by the kernel.

This thing is sticky, and I don't like it. I don't appreciate it.

Hey, its your mainboard and your system - I can only make guesses what the problem is. But I think it's worth the time finding the real problem instead of getting a new board.
i) A new board is not exactly cheep (if you want to get a decent one)
ii) If the problem still exists on the new board then you wasted money for nothing
iii) I doubt that a SATA channel dies without influecing the functionality of the board

If you want to give up, its your choice

I am a dolphin, do you want me on your body?