I swapped the motherboard and CPU and it *seems* to have gotten rid of the problem... games are now buggy though! LOL!

My bad, the test ran for 3 hours then gave a fatal rounding error. :surrender

Resolved!
 

I bought a new dual channel kit from Corsair (2x512MB PC3200) and I no longer have any problems. I guess when Memtest doesn't show an error, but you're still having problems, it can still be the memory. Prime95 runs like a dream now as well. Games are stable. With all the RMA's, it will have taken a few months!

THANK YOU! Everybody. :bow:

[QUOTE=thermalMan]I guess when Memtest doesn't show an error, but you're still having problems, it can still be the memory.[/QUOTE]

You´re absolutely right. That is the main lesson learned from this episode. There have been several examples of this situation in the past.

To anyone having similar problems, for god sakes, listen to these folks! LOL!