"Bios checksum error" after keyboard / mouse lockups

Hello.

Been having very, VERY annoying issues with my computer as of late. I could be playing a game. All is well until all of a sudden my keyboard and mouse just completely stop working (although the computer still appears to be running fine, just keyboard and mouse stop). So i restart my computer, only to get a message along the lines of "bios checksum error" with very fast, constant beeping. I reset my computer again and i get nothing on my screen, the light just turns amber. After turning my computer strait off and back on again, it comes back to life and begins working again like nothing ever happened. (until the next time it happens).

I am really struggling to find out what the problem actually is, but i THINK that it might be the motherboard, but im not sure. What do you guys think? Sound like a motherboard problem?

My system specs are as follows:

CPU: Pentium 4 2.2Ghz
RAM: 1GB DDR400
Video: GeForce 6600GT
HDD: 320GB WDC
Mobo: ECS 661FX-M (I know ECS is crap, this is why i think it might be the mobo)
PSU: Thermaltake 430w

Yes sounds like a motherboard problem.. the Bios Rom chip is most likely faulty.. You can try these tips...

ok, i appear to have fixed the problem now. I think my Northbridge was overheating. It use to have this really bad (seriously, the stuff turns to powder after a week) thermal grease but i replaced it with high quality silver thermal grease. Seems to have done the trick. Yay!