Crash893,
Ok, the only two things I can think of are:
Unless you purchased a nationally recognized brand name psu at compu usa, we need to know the brand and what the specs are from the lable on the psu, re: 12v,5v,and 3v outputs??
Have you tried with say only 1 or 2 sticks of ram?
And have you ran memtest on your ram, even at the underclocked speeds you are able to attain now?