Media players not disabling xscreensaver
 

I'm running Linux Mint 14 Xfce, and have replaced gnome-screensaver with xscreensaver (to gain functionality gnome-screensaver doesn't have).

Neither Mplayer nor Totem are preventing XScreensaver from activating while they're playing a movie. Totem's "disable screensaver when playing ..." option is enabled, and I'm launching Mplayer using this command line:
Does anyone know how I can make this functionality work?

Thank you for any help.