I've finished KOTOR twice and decided to have another go at it.
This time playing through, three of my characters (Handmaiden, Bao-Dur, and Mira) stopped gaining experience (when not with me) and the ability to gain or lose influence.
I'll explain the experience thing a little better. If those three are with me, they gain the appropriate amount of experience as anyone else would. When I leave them out of my party (on the Ebon Hawk) they do not have an increase in experience. Everyone else that I leave on the Ebon Hawk does though. Currently, Bao-Dur has enough experience to be on level 12, Mira is on level 16, and Handmaiden is at 19. Everyone else is at 21 (my Exile is higher of course).
I noticed that the characters that was affected by the experience became immune to influence effects also. For example, when I had Mira with me on Onderon I defended her after the second bounty hunter's remarks and nothing happened (even when I was leading with her to initiate the conversation) and when I sat back when the riot erupts. Both these events are supposed to increase influence with her and did not.
I didn't notice right away when this started to happen, but I think it wasn't too long after I made them Jedis that this started happening. Has anyone else experienced this or know how to fix it?