I'm finding that the audio becomes out of sync with the video after jumping forward by 10 seconds. It is very noticable, perhaps 500ms.
Hitting pause followed by play fixes the problem - I guess it re-syncs the system.
I am using S/PDIF and the problem occurs when streaming Dolby Digital and also when VLC is decoding the audio track (MP3).
I'm running Debian, ALSA and 0.8.4a. I've tried on my Windows box and it doesn't seem to have the problem, however that doesn't use S/PDIF so maybe that's the cause?