The headaches for Disney (NYSE:DIS) keep coming over John Carter. After flopping at the box...

The headaches for Disney (NYSE:DIS) keep coming over John Carter. After flopping at the box office, the movie was released on DVD this week with Disney promising rental giants that they would receive DVDs to rent after 28 days. But Netflix (NASDAQ:NFLX) and Redbox have jumped the gun, buying discs from suppliers such as Wal-Mart and Target to offer to consumers (at a loss) early - potentially undercutting DVD sales. It's all about leverage, as the uneasy relationship between movie studios and rental companies continues to be redefined.