I had a similar experience to yours on Onderon. Every time I went to talk to whatshisname the pazaak player in the cantina to solve the murder mystery, it would CTD when finishing the conversation with the guard captain. I persevered and rebooted my pc, tried a few more times. In the 5th attempt (and a couple of different dialogue paths), it got past the dead spot. It then repeated the process every time I walked out of the cantina, CTD more often than not, but after leaving Onderon for the first time, it got "stable" again.
Strange thing (didn't have any issues on Dantooine btw.).