diff -Nur -x '*.orig' -x '*~' gnome-media-2.30.0/gnome-volume-control/src/gvc-mixer-dialog.c gnome-media-2.30.0.new/gnome-volume-control/src/gvc-mixer-dialog.c
--- gnome-media-2.30.0/gnome-volume-control/src/gvc-mixer-dialog.c	2010-04-04 20:48:08.805975603 +0200
+++ gnome-media-2.30.0.new/gnome-volume-control/src/gvc-mixer-dialog.c	2010-04-04 20:51:49.445977310 +0200
@@ -748,9 +748,9 @@
                 g_free (name);
 
                 /* FIXME would need to do that in the balance bar really... */
-                /* Make sure we do not unmute muted streams, there's a button for that */
-                if (volume == 0.0)
-                        gvc_mixer_stream_set_is_muted (stream, TRUE);
+                /* Make sure we do both mute and unmute, see LP: #550195 */
+                gvc_mixer_stream_set_is_muted (stream, (volume == 0.0));
+
                 /* Only push the volume if it's actually changed */
                 if (gvc_mixer_stream_set_volume(stream, (pa_volume_t) rounded) != FALSE)
                         gvc_mixer_stream_push_volume (stream);
