[mythtv] mythvideo ffw/rwd not smooth and sound disable

[Bill]

By jumping I mean it ffw's for a few seconds, then pauses for a second or two, then ffw's a few seconds, etc.  Recordings and DVD ISOs are smooth.

A DVB recording played by through "view recordings" is smooth and no sound is played.  But if I take the same file (mpg) and put it under mythvideo, ffw is jerking as described above with sound and with the error messages "NVP::AddAudioData():p1: Audio 
> buffer overflow, audio data lost!".