Comment 3 for bug 1181828

For what it is worth, the exact same problem also surfaces on the Macbook Air 1,1. Everything seems to be working fine; sound card is recognised and alsamixer shows the various channels as active and unmuted. But no sound comes out of the speakers.

The problem for the Macbook Air 1,1 is reported on various sites, among here: http://ubuntuforums.org/showthread.php?t=2141179