Sounds like you have a qwuirky motherboard. The SATA drive works at 150 mhz compared to 100/133 of IDE drives. Seems like it's only faster in mhz, but I notice a big difference in response time compared to my old IDE drives. Have a little more patience in figuring out why you're having this problem, before throwing in the towel.
Check with support at Gigabyte (giga-byte.com) and see if there has been any mention of others having the same issues with SATA drives and your exact motherboard.
Do you have the most current BIOS flashed? I've heard of other SATA drive compatible motherboards needing the BIOS updated in order for them to actually work. Or maybe you did flash it with a new update before your started installing the SATA drive? If so, roll back to an earlier BIOS version.
Also, look in BIOS ... some motherboards boot order lists IDE hard drives before SATA drives. Maybe it's looking for an IDE drive and doesnt know to look for the SATA drive. Some motherboards list their SATA drives as IDE 3 & 4, which I know is odd since they're not IDE. But just some things to look for in your troubleshooting.