After switch on mute, no sound

[Raph]

When I switch off the sound "mute" with kmix it works, but after when I would like to go on, no sound!

Linux 3.0.0-12-generic #20-Ubuntu SMP Fri Oct 7 14:56:25 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux
Description: Ubuntu 11.10
Release: 11.10
kmix:
  Installé : 4:4.7.2-0ubuntu1
  Candidat : 4:4.7.2-0ubuntu1
 Table de version :
 *** 4:4.7.2-0ubuntu1 0
        500 http://ch.archive.ubuntu.com/ubuntu/ oneiric-updates/main amd64 Packages
        100 /var/lib/dpkg/status
     4:4.7.1-0ubuntu2 0
        500 http://ch.archive.ubuntu.com/ubuntu/ oneiric/main amd64 Packages

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: kmix 4:4.7.2-0ubuntu1
ProcVersionSignature: Ubuntu 3.0.0-12.20-generic 3.0.4
Uname: Linux 3.0.0-12-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 1.23-0ubuntu3
Architecture: amd64
Date: Mon Oct 31 19:31:20 2011
InstallationMedia: Kubuntu 11.04 "Natty Narwhal" - Release amd64 (20110427)
ProcEnviron:
 LANGUAGE=fr_CH:fr
 LANG=fr_CH.UTF-8
 SHELL=/bin/bash
SourcePackage: kdemultimedia
UpgradeStatus: Upgraded to oneiric on 2011-10-16 (15 days ago)