pff i am having big problems again :-(

I was overclocking my cpu and i got a corrupt bios (i don't understand how this is possible) i got it fixed.
But now its impossible to OC :s keep getting a boot block. I changed the bios to the 1704. (i was alway's using the 1406).
I mean could some one please help me out.... Its not like i changed alot but for example changing FSB to 340 causes boot block...