Here's one of the many clips where this has happened. We're winning this game by a fair margin, I get slept...I stall for a couple seconds in case I get broken out, I see I'm not targetted anymore, so I cast Purify at about 12-13 seconds left on Sleep. It does NOT get cast again, as you can clearly see there is no new spells cast on me. The Purify goes on cooldown, but the sleep stays in effect. My tank is then killed and we lose this game. This has happened to me in several games, almost every loss is because of some bugged out purify against a Whm. I'm really getting tired of it.

https://www.youtube.com/watch?v=Z_hyfzsXak0