how much was the 710? I think you should have gone with the 550. that is super stable with 4 cores, and was only $99 for a AM3 cpu!!
I would suggest getting the latest bios update from Gigabyte
I unlocked the 550 using the same mobo with the "F4" version. (5/21/2009)
hope that helps!
edit: remember that you need to enable the hybrid setting in the BOIS to unlock.