Numerous video stuttering and sync issues

[thecapsaicinkid]

I'm going crazy trying to sort out what I think are numerous separate playback issues.

Firstly my system;

Boxee v0.9.21.12563M
Ubuntu 10.04 64bit
Nvidia driver 195.36.24-0ubuntu1~10.04
Xorg.conf is the very basic one regenerated by nvidia-xconfig
nvidia-settings cleared


Different videos exhibit different problems influenced by my refresh rate 50 or 60Hz (as noted) and some issues are apparent in other players i.e VLC where noted.

DVB-T recording played as a regular file
Boxee 50Hz = stutter after 10min, audio out of sync
VLC 50Hz = fine

DVB-T recording played through Boxee MythTV source
Boxee 50Hz = audio drifts out of sync and never catches up
Boxee 60Hz = fine
VLC = fine

HD MP4
Boxee = fine
VLC = fine

R2 DVD
Boxee & VLC 50Hz = consistent stutter every second, noticeable in panning shots
Boxee & VLC 60Hz = intermittent but infrequent audio breakup and random stuttering

R2 DVD iso rip
Boxee 50Hz = fine



Any suggestions welcome.

Thanks