Ugh, that makes me think of the bug in Fallout New Vegas where, randomly, the healthbar of the awesomest companion in the entire game will drop from 240something to, like, 52. And will never go back up again. And apparently it happens WHEN YOU SAVE, so it isn't like you can just reload your last save when you notice it. We didn't notice it till a couple of saves after it happened, too, so we wound up losing like five hours of play time going back to when poor ED-E wasn't busted. (The plural is because with most games mecha plays and I watch/snark/do all the logic-puzzle-y stuff for him.)