That happened to me too, except for the fact that I got the bug in a different part of the game,
the part where your party rescues the main char outta the Yatch.
Atton wouldnt show up where he should, and I ended up in control of Bao Dur, and in the party selection screen I had another Bao Dur instead of Atton(that's why Atton wouldn't show up in Tubb's place, there was no Atton anymore!).
Unfortunatly I found no workaround for my problem, as even loading a previous save wouldn't work, and I had no save prior to the maze playing as the Wookie.
Oh well... I had to restar the game.