If you've played this game long enough, you might know that once you've recruited so many party members, any new ones you pick up will usually not be added to your roster and simply disappear. One annoying exception to this: There is a point near the end of Asellus's quest where you go through a door maze called the "Labyrinth of Darkness" or something similar. There is a turnip-like monster in there and if you talk to it, it will join your party when you leave the labyrinth. White Rose automatically leaves your party at this point and Zozma replaces her. The problem is that if you have a full roster of characters and talked to that turnip, it will overwrite one of your other characters when it joins.
Taken with permission from Flying Omelette.