sacrifice fps problem

[spidey_joe80@hotmail.com]

when i play sacrifice my fps are always going below 30 nomater what the resolution i even put it on 600x400 just to check then at 1900x1400 :) but still the fps were about the same tthis doesnt make any sense. has anyone else had the same problem?
athlon xp 1.6ghz
g3 ti500
512mb
i instlaled the nvidia refresh fix and have the latest drivers 2312
any ideas?