Brave New Films has a short video on McCain's notorious anger management issue and how it could be a national security problem. Of the several people interviewed for the piece who described incidents, the most shocking is one in which a witness says she saw McCain "back-hand" the relative of a missing Vietnam soldier who was trying to get time with the Senator to discuss POW/MIA issues. The piece then highlights sections of a "report" on the incident, but this Daily KOS post on the story explains something far less violent, if still incredibly dismissive.
This is obviously not the first time McCain's temper has come into play. In fact, these stories supplied the foundation of a Bush-Rove whisper campaign alluding that McCain was mentally unstable and unfit to serve as President. Now that McCain has employed Rove's staff it's a little poetic justice that their smears are coming back to bite them.