Are you guys trying to use Melee and Magic at the same time? Or just everyone hitting the same aura, and when everyone does, that is when it has problems? I've heard that they put in something to prevent using multiple types of auras at the same time ... assuming that is true, and the latter situation describes your problem, then there could be some sort of conflict where the game sees multiple copies of the same aura and tries to deactivate (some of) them?