For the quest Put Farmer John to Rest - 6384: In a group of 3, all having the quest, the group leader used the charm on Farmer John. He despawned and respawned as he is supposed to. One of the other group members had the charm removed from his inventory and was able to complete the quest. The other two group members still have the charm. However, John will not speak to us (just tells us to go away). Using the charm causes him to attack, but the charm remains in inventory and the quest cannot be completed.