Hello, i just set up fresh clean mythbox running ubuntu feisty (7.04) and myth backend and frontend. I have a PVR-500 video capture card that captures via hardware encoders. I have Totem on the system as well (ubuntu default media player)...now to the issue:

When i play any video file back, in either mythtv or in totem, the audio slowly goes out of sync...so for example, for the first 5 minutes, the audio appears in sync, but the longer you play the file, the less in sync it is, so by around 20-25 minutes, it's out of sync by about 1/3 of a second, by 45-55 minutes, around 1/2 second out of sync. These mpeg files are not being recorded through the soundcard, so it is my understanding that there should be no out of sync problems. Also, i tried ripping a few dvd's in myth and they too play out of sync the exact same way when played in either program.

I'm using a P4 2.8ghz sony vaio, 512mb ram, nvidia fx5200 agp video card, and onboard optical output (the analog output gives the same problem, so i know it's not cause of the optical).

Please, can anyone lend me a hand...i've tried tweaking all the settings i know of. Now here's one weird thing...if i rip a dvd to an iso file and play it in myth, it plays flawlessly, no out of sync problem. Go figure.

-Thanks for the help.

When you rip the dvds, do they create more than one VOB file? If they are, your problem could be (at least as far as ripping dvds goes) that something is going wrong when you are joining them together.

Myth DVD has a few settings for ripping: ISO, Perfect, Excellent, Good....the iso creates one .iso file, the other three create one .vob file, just different qualities. I can't get any of the .vob ones to stay in sync. The .iso plays fine. So to answer you, no, they rip into one file, no joining is done.
-Thanks