[mythtv-users] mythtv skipping - can't track down why

[Norman Lyon]

I'm hoping someone can provide me with some ideas as to what's causing me
problems with mythtv playback.

I'm having problems where every few minutes, my system skips approximately a
quarter of a second of both video and audio.  If I back up and replay it, it's
fine, and I don't seem to have the same problem with my desktop.  Problems seem
to happen whether I'm recording or idling in the background.

I'm using 2.6.7 on an XP 2400+ (256k L2) 512MB RAM.  Top shows playback at about
15-20% CPU utilization, and problem system is not used for anything else.  Video
card is Nvidia MX 440, 64MB RAM in AGP 4x.  Nvidia driver is at version 6629.
Myth version is 0.17-3 from the Debian archive at
http://dijkstra.csh.rit.edu/~mdz/debian.  DMA is enabled, Xvideo is active,
filesystem that nuv files live on is a XFS FS on a LVM volume (for possible
future growth) on a new 7200 RPM IDE drive connected to a Promise PCI IDE
controller (no other devices hanging off of controller).  Window manager if
xfce, and system daemons are pretty minimized (running a mysql database for
mythtv itself, ntp client, etc).  Resolution on my VGA output is 640x480 @
24bit (sending to video out box since it works better than the onboard video
out).  Iostat isn't showing more than 2-3 transactions per second on the
dedicated hard drive.  Audio drivers are OSS for 2 CM8738 cards (1 for output,
1 for recording) - alsa only likes 1 of the cards, and neither OSS nor ALSA
like the onboard.  Capture card is a cheap bt878, and I'm using lirc for input
using the capture card, and as an IR blaster via a USB-DB9 converter.

The desktop that has no problems with playback as a frontend client (but isn't
attached to my TV) is an XP 1900+ (256k L2) 756MB RAM, and alo doubles as my
primary server (so it regularly gets hit with requests on a random basis. 
Video card is ATI 9200LE with 128MB RAM in AGP 8x @ 1600x1200 @ 24bit.  Video
display on this system is full screen.

I'm starting to run out of ideas, and would love more ideas on things to look at
to get rid of this intermittent skipping.  I do plan on trying a 9200LE from
another third system (in a few days, if nothing else comes up) to see if the
Nvidia card is the problem, since I've had nothing but great luck with ATI, and
only so-so luck with Nvidia.

Thanks,
Norman