does xp run 3dmark 03 better?

[tasty danish]

i ran 3dmark 03 with xp installed and scored 6300 marks (roughly)
i installed 2k and reinstalled all my drivers etc. overclocked the card to the same speed, everything is the same as it was before just on 2k.
however my score is now 5600. i noticed the cpu test 2 was really slow (the one with the trolls).
is it possible that xp hands out cpu clocks more effectively to 3dmark03 than 2k does? my games dont run any slower, faster if anything (more system resources).
setup:
windows 2k
2.4c @ 3.4
1gb geil pc3500 platinum
120gb maxtor sata
radeon 9800 flashed to pro
asus p4p800 deluxe

thanks everyone

[mobo57]

Must be in your set up. Iam running W2k with SP4 on my system and I score 6100 to 6300 normally. It does go real slow in that test though.

3200 XP
1 gig corsair ddr 3200c2pt
ATI 9800 pro
K7n2 Delta ILSR