Leaping Coffin Boxes

So Elaine's coffin box that she made decided to leap from its hanging place over the den door again. It's done this multiple times now. Nothing else has every fallen off these sills, and the coffin box is especially firmly affixed. Last time she repaired it I practically hung from it to make sure was well seated on the nail that holds it in place. We've joked about some "previous occupant" disliking the coffin and I'm running out of reasonable explainations for why this item — and nothing else — should keep falling down.