I also had this problem, which I worked around using 'alsamixer -c0' and unmuting things.
This is particularly pernicious because the default sound control that Jaunty provides doesn't have these mute buttons, at least for my hardware, nor are they apparent when I run just 'alsamixer'.
(My hardward is a Dell Inspiron 1420N laptop, which apparently has HDA Intel STAC 92xx Analog hardware (?)).
Also, I wonder if pavumeter and pavucontrol shouldn't be installed by default--they seem handy.
I also had this problem, which I worked around using 'alsamixer -c0' and unmuting things.
This is particularly pernicious because the default sound control that Jaunty provides doesn't have these mute buttons, at least for my hardware, nor are they apparent when I run just 'alsamixer'.
(My hardward is a Dell Inspiron 1420N laptop, which apparently has HDA Intel STAC 92xx Analog hardware (?)).
Also, I wonder if pavumeter and pavucontrol shouldn't be installed by default--they seem handy.