I've had some funky experiences with Gigabyte boards. I got a
GA-7IXEH, see my sigpic for more on my rig.
This particular board model had a outdated BIOS on it, if u installed a Duron 1.3 (and it just so happened out of all the speeds from 550 to 1.4 I got a 1.3) it would post as a Duron 750. I flashed the BIOS and fux0red the thing up (oddly enough, GB boards have a Dual BIOS feature on them. This one didn't) so I RMA'd it and got it back a week ago. If it's a new processor, it could be a BIOS error, if not, check ur
FSB.