Reports are the latest PS3 firmware, adds a check to stop "pirated" movies from playback, using a special check on the "audio" track of your DVD-video or Blu-Ray recordable.
This check called "cinavia" has been around since v3.10 firmware, but it seems it is more enabled in the latest firmware, maybe even checking content on your HDD, maybe one of the reasons for so many "bricked" PS3 at 99% looping or crashing with an weird 800x error code.