Hi, Varus,
Frequently, quest turnins are at inconvenient places (like back at the beginning of the dungeon). When placed at inconvenient places, Dungeonbuddy cannot get back to them before the group is likely to break, and you get kicked out of the dungeon. Sometimes, Dungeonbuddy decides it can probably exit and re-enter the dungeon (you're always placed at the entrance when doing this) to get back to the quest-givers quickly.
Dungeonbuddy uses some discretion in determining the actions to take regarding turnins. If it fails to turnin, Dungeonbuddy will turn in the quests the next time your pass through the dungeon.
cheers,
chinajade