This worked for me and I don’t know if will work with others, but here it is my solution
First of all, you have to edit /etc/modprobe.d/alsa-base.conf
sudo nano /etc/modprobe.d/alsa-base.conf
search for this lines
# Power down HDA controllers after 10 idle seconds
options snd-hda-intel power_save=10 power_save_controller=N
and put a # before it, and will look like
# Power down HDA controllers after 10 idle seconds
# options snd-hda-intel power_save=10 power_save_controller=N
After each reboot, you will have to do this
sudo alsa force-reload
alsamixer
In alsamixer you will have to unmute the Master, Headphones, PCM, Center and LFE. And sound got fixed! I hope this works, but this will be fixed on coming days (I suppose that needs to before Karmic Koala release)
Looking on IRC I have noticed many people is getting problems with sound here I will add information that might work for more people.
Mitac computer (Polarina@freenode) with 00:1b.0 Audio Device: Intel Corporation 82801H (ICH8 Family) HD Audio Controller (rev 03) added the following line in /etc/modprobe.d/alsa-base.conf
options snd-hda-intel probe_mask=1 model="basic"
(Not sure if that probe_mask is required).

