Game crashes when switching to prestiege class

[jimmoy]

The game crashes whenever I enter the "powers" section of the level-up screen, but only when switching to a prestiege class. The game is fully patched (in fact this didn't happen during my other play-throughs, before I installed the patch), and my drivers are up to date (though it is an ATI card).

 

I've just finished Nar Shadaar, am a level 17 (a couple of levels late, I know) light side jedi guardian (don't know how much of that's relevant).

 

If anyone could please help, it would be very greatly appreciated.