So this is not the first time this has happened to me, and it has happened to many people I know. When your gear breaks after you repair it is missing a majority of its gems and enchants. Relogging and zoning fixes it. Has Blizz made any official comments on why this happens and if they plan on doing something about it, because when you are in the middle of Sarth +3 attempts and suddenly your DPS drops 300, well lets just say irritating is a polite way of putting it.