I just experienced the same problem after booting 3.8.0-18-generic for the first time. When booting the previous kernel 3.8.0-17-generic sound works as expected. The bug must have been introduced by the latest patch-set.
I just experienced the same problem after booting 3.8.0-18-generic for the first time. When booting the previous kernel 3.8.0-17-generic sound works as expected. The bug must have been introduced by the latest patch-set.