I was watching my brother playing his White2, and he was fighting Iris. Apparently, the life orb that her Druddigon was holding only made the Pokemon take damage if it used Dragon Claw (I think that was the move; I can't remember) It also wouldn't receive damage from the life orb if it used any other move.
Is this a glitch, or does it have something to do with Druddigon's ability, or something different?