I had problem with sound on my new Acer Aspire 8920. Following script method from this page I lost master button on panel. But fortunately there was simple way to get all working and I found it on launchpad written by guy called Jojo and now everything work like it should.
This is what I have done:
Install fresh Ubuntu 8.10
Update system and reboot
Install proprietary graphics driver for NVIDIA cards (177) and reboot
Open terminal and type:
Add this to the end:
sudo gedit /etc/modprobe.d/alsa-base
Reboot and it works perfectly on 5.1 integrated speakers and on headphones too.
# added by myself
alias snd-card-0 snd-hda-intel
options snd-hda-intel model=auto
Bye Bye Vista...