A thread over at the AVS Forums has highlighted a potential problem with the coating of Blu-ray discs, described by many as "disc rot" due to the mould-like spots that have made several owner"s Blu-ray discs unplayable. The five page thread has reports from dozens of forum members, many of them discovering spots which can"t be rubbed off on Blu-ray versions of "The Prestige." It"s impossible to judge how widespread the problem is from a single forum thread, although it"s not unheard of to see a product recall after a problem is discovered by users on a forum.