I was thinking the same thign as a bunch of the people up above. You should be getting a higher score. I can get that score with my system...
AthlonXP 1800+
256mbs DDR pc-2100
ATI Radeon8500 64MB AIW
You should be getting 8000+ 3dmarks. I'd say something was really holding your system back, and inadvertantly you fixed it! I'd tweak it some and see if you can't hit 8000!