There's this glitch in Celestia I've encountered twice now, if your on a quest to go to someone's lair and defeat them, you may have teleported out on accident so to teleport to your friend who's in there, and you defeat the Boss and go on your way out and then the Boss Monster says something and now you need to defeat the Boss, and I've had to re-defeat a Boss once but I haven't gotten to the second one just yet. Can someone please help me with this? It's gotten very annoying and I for one am not to crazy for it.
That's not a bug. That's you failing to get the proper quest. If you want to teleport into an instance like this, you need to enter on your own first and hear the speech to activate the "defeat" part of the quest. THEN you can port to your friend and fight together.