[mythtv] playback stutters after pausing (xvmc?)

[Preston Crow]

When playing back recordings from my PVR-250 with xvmc enabled, I get a
weird stuttering effect in the video, but not the audio, after pausing.
This happens probably 80% of the time when I pause, and is always
rectified by skipping backwards.

The same happens with live TV, and I think I've seen it with HDTV
recordings, but I'll have to verify that if it's important.

This didn't happen with 0.17, but it has been happening for quite a
while now.  I'm running a recent -svn build, and I'll update or try
patches as appropriate.

--PC