Comment 5 for bug 378372

Howdy, and thank you for opening a ticket to help improve Mythbuntu.
You'll find two different errors listed in your logs. The first one makes it look like at least your preview files have been transcoded, or otherwise do not have seek tables.

2009-05-19 16:26:23.489 AFD Error: Could not find codec parameters. file was "/media/dati/live/3201_20090519162603.mpg".
2009-05-19 16:26:23.489 Couldn't open decoder for: /media/dati/live/3201_20090519162603.mpg
2009-05-19 16:26:23.489 NVP, Error: JumpToProgram failed.
2009-05-19 16:26:23.492 TV: Attempting to change from WatchingLiveTV to None
2009-05-19 16:26:23.542 NVP, Error: Unknown error, exiting decoder
2009-05-19 16:26:27.557 TV: Changing from WatchingLiveTV to None

If you look around that same time, and afterwards in the mythbackend.log, you'll find various error messages about not being able to open file(s) for playback, including:

2009-05-19 16:27:41.354 Delete Error '/GetPlaybackURL/UNABLE/TO/FIND/LOCAL/FILE/ON/tzoot/2024_20090516161506.nuv'
   eno: No such file or directory (2)
and

2009-05-19 16:28:24.902 RingBuf(/media/dati/live/11018_20090519162622.mpg): Invalid file (fd -1) when opening '/media/dati/live/11018_20090519162622.mpg'.
2009-05-19 16:28:24.917 RingBuf(/media/dati/live/11018_20090519162622.mpg) Error: Invalid file descriptor in 'safe_read()'

These look like either transcoding problems or database issues.
Are you still having this problem, and if so, have you run a check on your database?

You may get more interactive help at the mythbuntu forums.