Thanx for answering,
but i have found alone a solution
I installed manually the latest version of alsa as described here : http://www.alsa-project.org/alsa-doc...&module=cs46xx
After that, there was no sound either .. but I tried another program instead of aumix : the KDE's mixing tool Kmix.
I increased the equivalent of "pcm volume" (the wave symbol) and the music played oh
I think as you it was aumix that bugged
(sorry for my poor english)
Now i have another problem : my headphones produce no sound (even if their volume is set to max)