Index: gnome-control-center-3.4.2/panels/sound-nua/gvc-mixer-dialog.c
===================================================================
--- gnome-control-center-3.4.2.orig/panels/sound-nua/gvc-mixer-dialog.c	2014-03-13 16:16:03.291570375 +0800
+++ gnome-control-center-3.4.2/panels/sound-nua/gvc-mixer-dialog.c	2014-03-13 16:35:51.883553147 +0800
@@ -1382,6 +1382,7 @@
 		return;
 	}
 	add_input_ui_entry (dialog, in);
+        active_input_update (dialog, in);
 }
 
 static void
@@ -1445,6 +1446,7 @@
         found = find_item_by_id (GTK_TREE_MODEL (model), id, ID_COLUMN, &iter);
         if (found) {
                 gtk_list_store_remove (GTK_LIST_STORE (model), &iter);
+                gtk_widget_set_sensitive (dialog->priv->input_bar, FALSE);
         }        
 }