P4C800 - benchmark results always different

Hi Forum,

i am using a thermaltake box, enermax 450W power supply, p4c800 bios rev. 1.10, 2xcorsair xms3200cl2 dual mode and a p4 3,0Ghz FSB400.

When i first got this i made a testinstallation with xp and just ran benchmarks all day, to be sure the hardware works.

I used PCMark2002, 3dMark2003, AIDA32 and Sandra. All worked fine. Memtest didnt show memory errors either.

Then i set up my "real" windows, installed newest drivers, my proggies etc and ran benchmarks again...but they are not "stable", they change all the time. Example PCMark2002:
Normally (roughly) CPU:8000 Mem:6000 IDE:1400.
Then, next Test i got CPU: 4000 Mem:3000 IDE:1400. Why???
Restart and i got the same low results. When i repeatly do benchmarks, some are the normal values, some are the lower ones.

Same with AIDA32 and the memory bench: One time i am top of list, one time i am way down at the list, near bottom (even un.der an Athlon 1200 with PC100 memory)

Sandra the same. I dont find any clues what could be wrong. Used Setup defaults, flashed bios new...but there the values show correct.

I would like some help here, really.

Thanks.

Edit: Formerly i used mem settings of: 2,5-2-3-5 (couldnt go faster). But now no matter what i do, it doesnt seem to have impact on the benchmark results anymore. Even speed, same problem, no effect on results.