I think we have finally worked out an audio scenario which works on nearly everything, in every program, ootb. The only things I would expect this to not work on, are a handful of new stuff which requires a kernel upgrade. Here is the problem... if the new schemes come to be via upgrade instead of install... it never makes its initial guesses, which work pretty good... so you may have to do a couple of steps. If you upgrade, and you have never seen this screen before:
You will need to run avwizard, so that you can choose the card you want, populating the database with this variable. I would move your /etc/X11/xine.conf to backup and just reboot.
Also please be aware of this wiki http://wiki.linuxmce.org/index.php/Audio_in_1004
There are circumstances where you will need to add AlternateSC = 1 or 2 to pluto.conf before audio will work. Again... we take guesses, and they should be pretty darned accurate... but we only do them once, during install, when conditions can be evaluated, and not overwrite manual decisions. As the code did not exist when, for instance, your video card was installed, these guessing routines never run.
If while in AVWiz, you do not hear audio, you can back up a step with the esc key, add/change the AlternateSC variable and go forward again. If it will work... it will work.
There are a couple of scenarios on the fringe in which the above will not work. If while trying to start avwizard, you have such a broken /etc/asound.conf file that alsa has crashed... and cannot be used to get data. Just delete your /etc/asound.conf it is rewritten every boot anyway... or if you have some odd in-between stuff written to the /etc/pluto/xine.conf that the scheme cannot replace. You would just delete the last 3 or 4 lines underneath
#vcd.title_format:%F - %I %N%L%S, disk %c of %C - %v %A
at the bottom of the file.