Keep getting Kaffeine errors when ending a video
 

Every episode of this TV show ends up getting this error:

The source can't be read.
Maybe you don't have enough rights for this, or source doesn't contain data (e.g: no disc in drive). (Error reading NAV packet.)

It's not bootleg or copied, I bought it at Best Buy. The show seemed to have been working for some seasons, but somewhere I am now getting that message after each ending of the show.

using mandriva 2006, kaffeine for DVD playback.