Gandalf and the balrog glitch

Playing multiplayer on Wii, one player is gandalf fighting the balrog, the other is the rest of the fellowship in the mines, however they actually only have three of the characters and can't be legolas, so can't hit the targets needed to move on. Once gandalf could be switched for legolas, leaving legolas fighting the balrog and gandalf back in the mines, but they couldn't be switched back. We can't move on without legolas but we have no way to switch to him. Has anyone else had this?