ya, the engine is just slow.
i never drop below 50fps on half-life 2 at full detail, and yet with kotorII i never get more than 30fps. i think it has something to do with it being made for xbox. cuz halo pc does the same thing, i usually never get more than 30fps out of it. yet my computer a custom built awesome-o rig.
thank god... i just got the game yesterday and it's already crashed like 12 times...
and my hardware is more than qualified to run it. i can run hl2 at 1024x768 at full detail with AF and AA on flawlessly