Are you sure you flashed the correct BIOS file for your board?
Have you checked to see if there's a hardware jumper to reset the BIOS settings? Maybe the previous settings have borked the update somehow.
Is it one of the ASUS motherboards that supports BIOS recovery (flashback?) via USB flash drive?
If not, is it one of those motherboards that has a dual BIOS with a recovery jumper?
Back in the day, I recall people doing something really sketchy called "hot flashing" the BIOS. Basically, it involved finding an identical motherboard, booting it up, pulling the BIOS chip WHILE THE PC WAS RUNNING (I know WTF, right?) then plugging in the dead BIOS chip and re-flashing it. Personally, I think this is nuts, but people did it.
More info... http://www.overclockers.com/forums/showt...rking-BIOS-Chip
Assuming your board has a removable BIOS chip, maybe you can find someone to re-flash your chip with a programmer or something. Or contact the manufacturer, maybe you can purchase a new pre-flashed chip.
GroovyMAME support forum on BYOAC