Comment 2 for bug 449762

Can you post the output of:
sudo fuser -v /dev/dsp* /dev/snd/*

I had this problem, and noticed the lirc daemon had hooked itself to the /dev/snd/ device, resulting in pulseaudio being unable to load my soundcard. After doing:

sudo update-rc.d -f lirc remove

Than I got sound after rebooting. Now I only need to get to start lirc after pulseaudio starts, but that's another problem