I haven't played KOTOR2 in ages, so my facts and planet names will be way off.
At the start of the game when you wake up on that planety space station, you get to the point where you get to the caves. I can barely remember when this happens, but at one point (on the Xbox game) it would freeze completely and stop you from going any further. I managed to solve the problem by getting a new disc, though.
What I'm wondering is...has anyone else encountered this issue before?