Comment 3 for bug 1131220

StacktraceTop:
 gvc_mixer_control_lookup_device_from_stream (control=control@entry=0xb977fb10, stream=stream@entry=0xb97aa0e0) at gvc-mixer-control.c:272
 gvc_mixer_control_set_default_source (control=control@entry=0xb977fb10, stream=stream@entry=0xb97aa0e0) at gvc-mixer-control.c:356
 gvc_mixer_control_change_input (control=0xb977fb10, input=0xb9ab96a0) at gvc-mixer-control.c:681
 on_input_selection_changed (selection=0xb971f000, dialog=0xb9a6e030) at gvc-mixer-dialog.c:1505
 g_cclosure_marshal_VOID__VOIDv (closure=closure@entry=0xb99b75a8, return_value=return_value@entry=0x0, instance=instance@entry=0xb971f000, args=args@entry=0xbf66bc3c "\034\252K\267", marshal_data=marshal_data@entry=0x0, n_params=n_params@entry=0, param_types=param_types@entry=0x0) at /build/buildd/glib2.0-2.35.7/./gobject/gmarshal.c:115