I have had problems with ALSA sound whenever I install and start using a new kernel. Here is what I do to make it work each time. It is here mainly for my records and help for others.
Run alsaconf to reconfigure ALSA for your soundcard and loading of appropriate kernel module.
Stop ALSA: ~$ /etc/init.d/alsa-utils stop
Delete the file asound.state: ~$ rm /var/lib/alsa/asound.state
Restart ALSA: ~$ /etc/init.d/alsa-utils start
This makes ALSA behave normally and sound is back again.