SATA HD detection problem - AN-M2HD

This MOBO won't detect my new 1TB WD HD. I've switched cables, sata ports, etc. and checked the HD on another box, where it is detected. Sata is enabled, as my sata dvd-rw drive shows up and runs fine. Any thoughts about what to do? For accuracy's sake, the HD did get detected once on this system, and I formatted it in Win XP. This was after many tries to get the drive detected. I called WD and somehow with phone support, we got it to show up. Next reboot, it's vanished again.

Thanks