Can't share audio in ALSA

[Gerardo]

Reinhold Rumberger wrote:

> The symptoms you describe are in themselves rather unusual. Normally,
> when some app blocks the soundcard, no other app can use it. In your
> case, the next app that comes along seems to steal the lock on the
> sound card, which is strange.
> Can you verify that you have xine selected as backend on phonon and
> that your other apps like mplayer are configured to use alsa?
> Also, can you open kmix and watch it when this happens? I'd like to
> know whether you can spot any strange settings or movements of the
> sliders when this happens.
>
> Other than this I don't know enough about sound to have the slightest
> idea what might cause your symptoms. I only just know enough to have
> noticed the error in Basil's statement and also that he seems to be
> confusing your problem with a much more common one.
>
>    --Reinhold
>

On Settings -> System Settings -> Multimedia -> Backend I have Xine as 
the only available backend.  Also I don't see the sliders moving at all.

I'm not sure if this might have something to do, but I have three audio 
devices.  HDA NVidia (my sound card), Conexant CX8801 (PC-HDTV 5500 TV 
tuner card), and USB Device 0x46d:0x807 (Logitech Webcam microphone). 
When I get a chance, I will unplug the TV card and the USB camera and 
see if the problem keeps happening.