Blue screen?

Hi everybody!
Recently, my Asus M2N MX AMD 64X2 4400+ MoBo has been giving me problems... yes... you guessed right- blue screen  

So I've learnt this means there's something wrong with my BIOS but since updating BIOS is both risky and an absolute last resort, I instead tried a lot of other options like reinstalling the OS on the same harddrive, then on a new harddrive, later reinstalling a different version of Windows XP, in addition to disabling my graphics card, trying out a different SMPS and so on.

Somewhere in those mad experiments I happened to remove all additional memory (three 1GB DDR2 533MHz DIMM modules to be precise) and used just ONE CARD (the original setting) to run the system- the computer worked without a hitch and I could reinstall XP without any errors in the process (when I tried reinstalling the OS with the additional RAM, the operation failed most times and in others, some important system files never got copied)

After reattaching additional RAM- I started running into problems like the browser crashing or operations failing seemingly because of memory problems and ofcourse, the occassional blue screen. I get the feeling this is because when additional memory is used, the CPU fails to perform operations.

But what really is the problem here? Is it something to with the BIOS? Do I need to update it?

Any help is welcome