Follow-up post to this since there have been no replies maybe someone can me with this new information. I've been reading the mythTV forums and the mythTV wiki. The default playback profile that was setup on the MD up is CPU+ which uses XvMC to offload some of the encoding from the cpu. I changed MythTV's playback profile to 'Normal','Slim', or 'CPU++' and LiveTV works, although choppy sometimes, because those profiles only use software rendering (ffmpeg with xv-blit). So it seems that both my MDs (nvidia 6600GT and 7800GS) should be able to take advantage of XvMC but they crash.
I've checked XvMC using these instructions from the mythtv wiki
Checking your installation
You will have to reboot. To check if XvMC is properly enabled, run:
$ cat /var/log/Xorg.0.log | grep Motion
and you should see:
(II) Loading extension XVideo-MotionCompensation
If you try: cat /var/log/Xorg.0.log | grep -i XvMC your driver might also report loading the options such as:
(**) NVIDIA(0): Option "XvMCUsesTextures" "True"
with VIA SP13000 this will be:
(II) CHROME(0): [XvMC] Registering chromeXvMCPro.
(II) CHROME(0): [XvMC] Initialized XvMC extension.
Based on the instructions above it appears XvMC is correctly installed. When i try to watch liveTV with player profile that uses XvMC i get the following entries in the terminal window
(sorry noob poster as well, log snapshot in attachment)
The signal i'm receiving from the HDHomerun is OTA with an HD antenna. Anyone have any idea how I correct this issue?