Comment 34 for bug 449855

slight update and a work around for skype this is on an aspire one but its similar enough to help I think

in /etc/modules

I added the line snd-hda-intel model=acer

there are a number of alternative models that may help the difference largely is the availability of a connector for inputs which will exist in some configurations but not in others when you select sound preferences.
not sure if its needed in
/etc/modprobe.d/alsa-base.conf

My real issue was and is skype since it doesnt allow the selection of input in its preferences and at best I could only get a very very low output from the internal microphone.

As a work around for skype may I suggest you launch skype with this command

/bin/sh -c "PULSE_SERVER=127.0.0.1 skype"

Skype will not be able to connect to the pulse server and will fall back to alsa allowing
 hda intel, ALC268 Analog (hw,0,0) to be selected.

I hope this helps, at least it is an improvement over uninstalling pulseaudio.