i was hosting a game. My character was grouped with and NPC and the other player was grouped with a different NPC. After saving and re-entering the mutli-player game the other player was the NPC he was grouped with and not the character he created. The character he created was now an NPC. Nothing we could do would rectify this situation. I could not dismiss the NPC as it would attack me.
A little more info, we were playing LAN style Multi-Player.