Comment 244 for bug 131133

By default, the Gutsy install cds seem to install a real-time kernel instead of the generic package. This means that anyone who installs from scratch will have to install the linux-backports-modules-rt package instead, or move to the generic kernel completely. That may be why the solution does not work for some users (it will work if you upgrade from Feisty because Feisty installs the generic kernel, at least for me. You still have to add the option snd_hda_intel etc. line to the alsa file as outlined by the wiki. So if the solution appears not to work, check that you are installing the correct backported modules.