Comment 18 for bug 535476

I have this same bug.

I have found a workaround.

$ sudo nano /etc/pulse/daemon.conf

Replace:

; default-sample-channels = 2

with

default-sample-channels = 6

(Note the removal of the ";" and the changing of 2 to 6 )

Now reboot or do: "pulseaudio -k"

And that worked for me.