Hello souljah and others,
Here is complementary info?
% ls -lisa /dev/dsp
12663 1 lrwxrwxrwx 1 root root 9 2004-02-16 21:24 /dev/dsp -> /dev/dsp0
% ls -lisa /dev/dsp0
2274 0 crw-rw---- 1 root audio 14, 3 2004-02-16 21:24 /dev/dsp0
% cat /etc/group | grep audio
audio:x:29:user1,user2
=> the 2 users, 'user1' and 'user2' belong to the 'audio' group.

Any solution for the problem I have (see description at the source of this post)?
=== Hypothesis:
In fact, I think what is happening is that when GNOME stops, in my current configuration, it doesn't stop the sound daemon (esd I think it is called) and hence the sound is not released for another user to use it in his turn...
Anyone knows which script should be modified? and how? Or maybe this is not the right explanation, any ideas/solution?
Cheers,
Sylvain.