Well, I spoke to soon. After installing gstreamer-ffmpeg, and creating an .asoundrc file, I thought everything was perfect. All my music applications were handling MP3s, FireFox was playing sounds, everything was sweet.
And so I played some music in Rhythmbox. That lasted about four or five songs, and then suddenly, the sound cut out. And at the same time, my keyboard became unresponsive. I could close applications with my mouse, but couldn't type anything in any application.
So I rebooted. And when I did, I got a "new hardware detected" old- school interface. It said my Kenwood Audio device had been removed, and I could either remove it's configuration, keep it, or do nothing. I chose to keep it. Then the boot up continued.
When finally logged in again, I tried playing some music. No go. So I checked the System Settings | Soundcard Detection utility, and guess what - the Kenwood device is gone. There are no more tabs, there's just one device option, the SB Live device which may or may not be the default motherboard sound device. In any case, it has no speakers and it's not the Kenwood Audio device, which is still attached to my computer and is the device I want to use.
What happened to my sound card and how do I get it back?
Dave