[mythtv-users] Sound issue that I can't seem to figure out

[Harry Devine]

OK, now that my video issue is resolved (via another post/thread), I'm 
moving onto my sound issue.  On my combined FE/BE Mythbuntu setup, if I 
go into Utilities/Setup->Setup->General->Audio (3rd screen), I have the 
following settings:

Audio output device: ALSA:default
Passthrough output device:   Default
Max audio channels:   Stereo
Upmix:   Passive
Enable AC3 to SPDIF passthrough (checked)
Enable DTS to SPDIF passthrough (checked)
Aggressive sound ca (unchecked - not sure what the full wording is; it's 
off the right of the screen)
Use internal volume (checked)
Mixer Device:   /dev/mixer
Mixer Controls:   PCM
Master Mixer Volume:   100
PCM Mixer Volume:   100
Independent Muting of Left and Right Audio Channels (unchecked).

When I tune to LiveTV, I get no sound, and the following in my frontend log:

2008-10-28 19:35:54.678 Opening audio device 'default'. ch 2(2) sr 48000
2008-10-28 19:35:54.678 Opening ALSA audio device 'default'.
ALSA lib control.c:909:(snd_ctl_open_noupdate) Invalid CTL /dev/mixer
2008-10-28 19:35:54.699 AudioOutput Warning: Mixer attach error -2: No 
such file or directory
                        Check Mixer Name in Setup: '/dev/mixer'

I can play music from within Myth fine, as well as get sounds from a 
terminal from outside of Myth.  I just can't get any audio for the TV.  
I have a pcHD5500 card and have it set to use /dev/dsp as it's audio 
device in the Capture Card setup for it.

Any ideas?
Harry