closed_captions,unknown_user_data.vob:

     First 15 MB of a VOB file which doesn't play quite right.  For 
     the 20 seconds or so, at the beginning it displays this message 
     a lot:
       "Unknown user data. 05 0B"
     And the video is apparently skipping backwards every few seconds 
     during that time.

     Then it starts to play perfectly and displays this message about 
     two times per second:
       "Closed Captions sample found! Contact MPlayer developers!"
     

     Later on in the movie, whenever the "Unknown user data" is 
     encountered, it does that skipping backwards thing.  I just 
     started learning about MPEG, but to me it seems like there are 
     two GOP or whatever for the same part of the scene, and you're 
     supposed to know which one to play (depending on the language or 
     something).  That would make sense where, in the movie, it is 
     displaying "Hell House" and "Hades" ('a' has an accento thingy), 
     but when it is displaying the "Dimension Films" logo, and in the 
     next scene where the back-skipping occurs, there is no visible 
     difference.  Maybe that "Closed Captions Sample" tells you how 
     to play only the one you want.  Hopefully someone can figure it 
     out.

closed_captions,unknown_user_data.mplayer-output

     Result from the command:
     mplayer -v -aid 128 -vid 0 closed_captions,unknown_user_data.vob \
     &> closed_captions,unknown_user_data.mplayer-output