diff -Naur mate-media-1.8.0-old/gst-mixer/src/window.c mate-media-1.8.0/gst-mixer/src/window.c
--- mate-media-1.8.0-old/gst-mixer/src/window.c	2014-01-20 20:41:30.513359308 +0200
+++ mate-media-1.8.0/gst-mixer/src/window.c	2014-03-25 23:05:49.958105676 +0200
@@ -110,7 +110,7 @@
 
   screen = gtk_window_get_screen (GTK_WINDOW (win));
 
-  if (gtk_show_uri (screen, "help:mate-volume-control", GDK_CURRENT_TIME,
+  if (gtk_show_uri (screen, "http://mate-desktop.org/", GDK_CURRENT_TIME,
   				&error) == FALSE) {
   	dialog = gtk_message_dialog_new (GTK_WINDOW (win), GTK_DIALOG_DESTROY_WITH_PARENT,
                                      GTK_MESSAGE_ERROR, GTK_BUTTONS_CLOSE, "%s", error->message);
diff -Naur mate-media-1.8.0-old/gst-mixer-applet/applet.c mate-media-1.8.0/gst-mixer-applet/applet.c
--- mate-media-1.8.0-old/gst-mixer-applet/applet.c	2014-01-20 20:41:30.509359288 +0200
+++ mate-media-1.8.0/gst-mixer-applet/applet.c	2014-03-25 23:09:26.204459419 +0200
@@ -1433,7 +1433,7 @@
     GError *error = NULL;
 
     gtk_show_uri (gtk_widget_get_screen (GTK_WIDGET (applet)),
-		  "help:mixer_applet2",
+		  "http://mate-desktop.org/",
 		  gtk_get_current_event_time (),
 		  &error);