I recently reformatted my laptop to run Ubuntu 12.04. I purchased the laptop new in New Zealand (default: region 4 dvd) and it came with Windows XP. I had no trouble watching local region 4 dvd's on the laptop under Windows. Now, with Ubuntu region 4 dvd's wont play. The error message says that the dvd's might be "encrypted". I can see the AUDIO_TS and VIDEO_TS folders, but Movie Player, VLC, and xine wont recognise the content.
Also, I checked and libdvdread4 is already installed.