The BIOS version that shipped on the board depends on your board revision. What is the AA number? You can find it on a label on the board itself. Refer to http://www.intel.com/support/motherboards/desktop/sb/CS-009009.htm
You can find the latest and prior versions of BIOS on this page.
My question is, how the BIOS got corrupted? Have you tried to upgrade BIOS by recovery mode?
Is probably the best way to upgrade or downgrade bios on this situation. Download the file named SG0121.BIO put it on a formatted pen drive.
Remove the BIOS jumper, put the USB pen drive on a USB port on the back not in a front panel of the case and turn the system ON.
Leave it for about 15 minutes.