[mythtv-users] ST61G4 box and annoying Prebuffering Pauses

[Zarkof]

Hello All!

For the last few months I've been seeing with prebuffering pauses (sound 
and video skips) that appear every few minutes or so when watching 
recorded programs. The hardware should have plenty of juice and other 
video playing programs (Xine / MPlayer) work OK.

I've gotten used to it, but it is an annoyance that I'd like to get rid 
off. I haven't seen any working solutions in the mailing-list archives 
and updating components does not seem to have any positive effects.

HW details:
* ST61G4 box - http://us.shuttle.com/specs2.asp?pro_id=432
* P4 2.8GHz
* 512MB RAM
* ATI Radeon 9200
* Matrox SATA 120 GB harddrive
* Hauppauge PVR-250

SW Details:
* Gentoo Linux 2004.1
* Alsa drivers 1.0.5a
* ATI binary only drivers v3.9.0
* ivtv 1.1.10-pre2-ck94d
* Myth v0.15.1

The CPU usage is around 10-15% when playing recorded programs. Also I've 
  tried all possible combinations in Myth in playback settings
* "Experimental A/V sync" -> after few minutes playback goes to fast
   forward mode and does not recover
* "Use video as timebase" -> similar symptoms as above, after ~10
   minutes video starts to speed up and audio is lost

Currently I have "Jitter reduction" and "Extra audio buffering" switched 
on and today the logs showed following when watching a recorded program:

-----
2004-06-20 14:12:51 Changing from None to WatchingPreRecorded
2004-06-20 14:13:45 prebuffering pause
2004-06-20 14:14:06 prebuffering pause
2004-06-20 14:18:03 prebuffering pause
2004-06-20 14:18:36 prebuffering pause
2004-06-20 14:24:47 prebuffering pause
2004-06-20 14:27:07 prebuffering pause
2004-06-20 14:29:22 prebuffering pause
2004-06-20 14:30:42 prebuffering pause
2004-06-20 14:31:57 prebuffering pause
2004-06-20 14:32:47 prebuffering pause
2004-06-20 14:38:34 prebuffering pause
2004-06-20 14:39:14 prebuffering pause
2004-06-20 14:40:36 Changing from WatchingPreRecorded to None
-----

Any ideas where/how to start debugging this? Thanks!