I just bought a 1.5 TB Seagate SATA II drive, and it's not being recognised at all by my BIOS (which is 3 years old, but still the latest version).
The motherboard is an Asus K8V-X which has a VT8237, so I jumpered it down to 1.5Gb/s and it made no difference in either sata channel. The two 300GB sata I drives that are in already are working fine. Seagate's diagnostisc disk doesn't see it either.
I'm wondering if it's likely to be a faulty disk or a problem with the Motherboard (maybe a size issue), I'm wondering whether to ask for a replacement, or try something else.
SATA is pretty foul proof. Plug in the two cables and go. If you have a working system, with two working SATA drives, then its probably the drive. (more so if you bought it off ebay.) Seeing as you can't test it in another system, I'd see about sending it back.