Don't forget to unmute the volume as well in alsamixer, the mute function can be toggled on (MM) or off (00) with the M button on your keyboard, with the relevant slider selected.
If that's not the problem, then perhaps give a bit more info, eg are you using kde? what is the e-mail program that does work? Is that the only one that works?
If you are using kde, have you tried playing around with the options in Settings>Sound & Multimedia>Sound System?
Last edited by tobyl; 03-31-2008 at 11:01 AM.