NF7-S v2.0+1.2

I'm experiencing great difficulties with this motherboard! It's always crushing down after I'm (or a software) changing the BIOS. For example, if I try changing it so that the CD drive will boot first, it's crushing down after so-and-so seconds. If a software (like MS XP setup) is changing it, the same happens.
I've isolated the problem after I changed the motherboard from NF7-s v2.0 to v1.2.

What should I do? I'm really tired with this!

AMD 2500+
OCZ 512 DDR 400