I run:
P4 3.4 Prescott @ 3.7ghz, X800XT Pci Express, 2GB Ram, Audigy 2.
Winxp Pro SP1, DX 9c, Omega Drivers (based on 5.1 Catalyst).
Same for me as many others, some problems with dantooine, but possible fix (helps me)
I run the game at 1600x1200 with AA and AF turned off. When I land on Dantooine, and look out into the distance, the game slows right down, if I try to run, its slo mo until I let go of run button, then I end up half way accross the map hehe.
The game would occasionally slow down even on the first planet.
What I do is Quick Save and then Quickload straight after. This usually fixes the "lag" until next time I have to zone somewhere (travel via the info terminals).
This also seems to of fixed my extreme low frame rate lag on Dant too. I will keep playing tomorrow and I hope it stays fixed
I think the quicksave and quickload thing has solved my problem, at least when the lag monster comes, it is quite easy for me to hit quicksave then quickload.
Hope that helps some others too