I knew it would happen sooner or later. A mod to have the bard in Solitude sing the YouTube version of "The Dragonborn Comes" screwed up my game. There was a crackling noise when anyone talked. I removed the mod and then I couldn't load any saves that used it. Kinda sucks.
Not really surprising, though, since it was done without the Creation Kit. I was going to put a warning up on the Nexus site about it, but they had already removed the mod, so I guess it nailed a bunch of people.