When running under a compositor, gnome-settings-daemon now uses an shiny translucent window for the volume OSD. But gnome-power-manager still shows the boring old OSD for brightness. Clearly, the two need to match visually.
commit d2251e9373add05113623c0a812a86bdd35d9116 Author: Richard Hughes <richard> Date: Thu Jul 23 12:05:43 2009 +0100 Use the same composited OSD for brightness notification. Fixes rh#512968