SATA 2 Port not detected

I have an Acer AX1920-UR10P.  It is my 2nd box because I liked the first one so much I bought another.

On this box, the factory has a DVD plugged into SATA 1 and the hard drive plugged into SATA 2 on the motherboard.

While using Win7 "delete programs" to get rid of the free junk on the system (...OK, I don't like that so much...) the system completely hung and wouldn't even respond to C-ALT-DEL, so I eventually restarted it via the power button.  When I did, it wouldn't boot, saying there was no hard drive.  It DID find the DVD drive, however, which would boot and read a DVD start-up emergency disk.  That tells me the DVD and its cable are working.

I restarted and went to the BIOS and found that SATA2 isn't detecting anything.

I opened the case and unplugged the HD from the SATA 2 connector and the the DVD from the SATA 1 connector, and swapped their SATA port connections.  (So now the HD is on SATA1 and the DVD on SATA2.)  On reboot, Windows comes up fine but now the DVD isn't found.  This tells me the DVD and HD devices and their cables are fine.  Checking the BIOS again shows nothing on the SATA2 port.  This tells me that for some reason, SATA 2 isn't working.

I cleared the CMOS memory via the mobo jumper, then used the BIOS screen to reload it to factory settings.  Again, SATA 2 isn't detecting anything attached.

What is important to note is that SATA 2 *WAS* working originally, because that is what the HD was originally attached to and the box booted from it just fine.  So, something in the BIOS or somewhere is preventing the SATA 2 port from detecting an attached device.

By the way, I ACER's help desk suggested I reload W7 from the emergency backup.  Duh.  Needless to say, that didn't do anything.