every things was ok this default ubuntu 6.6 installation (2.6.15-23), but with the last kernel upgrade (2.6.15-25 or 26), there is a bug and in log. acx: firmware 'Rev 2.3.1.31' does not work well with this driver That the difference between 23 and 25 kernel ? Tanks. -- Use later version of acx https://launchpad.net/bugs/22238