The most obvious solution to your problem is hot-swapping your BIOS and then flashing it again.
For hot-swapping, you've to find another motherboard that has the same BIOS chip as yours.
The procedure consists of taking out your BIOS chip, and then plugging it into the other motherboard while the board is running. Then you've to run the flash utility that you originally used to flash your BIOS. Provide it with the name of the file that you saved while flashing your BIOS (the older one). If you don't have that file, you can search Google for obtaining the latest BIOS update for your MB. You probably already have the updated file (as you mentioned). Once you've provided the bios file, flash it.
Various detailed tutorials are available on the process. You can search using google or post me a PM for any details you want.