[mythtv] How is audio handled differently then in mplayer? Trying to get sound internally.

[novamail at novanix.com]

I have a pvr-350 card.
If I do: mplayer /dev/video0 I get sound via the speakers hooked up to my computer, however if I watch tv or watch recordings the sound only comes out the rca connectors on the back of the card.  Is there a reason for that? I could have sworn the first time I set everything up I was able to get the audio out through my computer with myth.  I am just not sure why if mplayer can do it I can't get it working with mythtv.

Thanks,
Nick