Quote Originally Posted by Steedious
Just realized what it could be. Every time GR ability fails I have Spirit Warden in play. I think his ability is stopping Grave Robber's when I'm trying to retrieve an ally. That's the best explanation I have. Is that correct behavior?
Makes sense, but if it is working that way I'd say that's incorrect. Spirit Warden says that the opponent can't return allies from "their" graveyard to "their" hand. Says nothing about blocking allies from an opponent's graveyard to your hand.