I think your system with a GeForce3 on that score is too low. You should get much higher.. because I get over 8000 on my P3 1064mhz with a GeForce2 GTS. You might need to check your video card driver.. maybe get the lastest one or else. good luck.
emm.. or I could be wrong.. maybe the GeForce3 is more optimized for 3Dmark 2001, not so much on the 3Dmark 2000. Like what the other guy said, try run your system on a 3Dmark 2001 and see what score you'll get. let us know..