Have you downloaded the latest patch (in other words, have you downloaded a patch in the last 2 years or so)?
If so, have you played the game on your computer before and had it work okay?
Have you tried reloading from your last save point and running through those scenes again?
If you answered 'no' to questions 1 and 3 then try that and see if you can get through the scene. If you answered 'no' to question two then it could be that your computer is having an issue with the game software (or maybe just an issue with itself). Regardless, if you've downloaded the most recent (and I 'recent' loosely since this is a fairly old game now) patch and tried reloading from a previous save and still can't get through, there's not much else I can suggest.
If you've tried those things, but still aren't having any luck, go here:
http://swforums.bioware.com/viewforum.html?forum=80
It's the Bioware Kotor tech support forum. You might have to sign up before you can post your question, but you stand a good chance of finding someone who knows how to help you there (as good a chance as anywhere else at least).
Sorry I can't be more helpful. Good luck!