that score sounds reasonable, i get about 12000 but thats with a gf4 ti4800 with 128Mb
that ati card is fairly old now so i'd say u wouldn't get much out of it
Have you tried up[censored] the bios on your motherboard?
I have had a problem with my gf4 ti4800se on a gigabyte ga-sq800 ultra
and the latest update seems to have fixed the problem.
Try up[censored] your mobo bios