Hi, It seems that the CS4231 sound problem is related to the kernel version. I'll try to upgrade from 2.6.8 to 2.6.15. Would you advise the safe procedure to upgrade it? I search this group and I'm confused. There is no package in stable package when I try to get it from Synaptic or aptitude. I just download a .deb file. Am I simply run dpkg -i to install it? If there is a problem, i'd like to switch it back to 2.6.8. Is it possible? Please advise. Regards, kwy