http://imdb.com/news/sb/#film3
“Sony Pictures Home Entertainment has discovered the source of a problem in their recent DVD releases that prevented them from being played on some players, including some manufactured by the consumer electronics division of Sony itself. The company said the problem was caused by an update of its copy-protection system, which it continually updates in order to derail potential hackers. Among the DVD movies affected were the new James Bond film Casino Royale, The Pursuit of Happyness and Stranger Than Fiction. Sony said that anyone who had purchased one of the discs and has experienced problems playing it may receive a replacement disk free of charge by phoning 800-860-2878.”