Xubuntu hogging desktop background

[tcll5850]

so I was looking up how to get a screensaver as a desktop BG and ran across this:
http://blog.prashanthellina.com/2007/08/22/matrix-desktop/

the trick seems to work as dragging windows seems to cough a tad.
(this is expected while running an OpenGL screensaver on top of an OpenGL compisitor)

problem is, I can see it because XFCE has it's background over the actual desktop.
how can I disable this??

thanks :)

[tcll5850]

just wanted to update, I've found this:
http://inspirated.com/2010/11/17/howto-use-animated-xscreensaver-matrix-backgrounds-with-xfce

but the drawing order isn't correct and it overlays my desktop entirely...
interacting with my desktop causes my original desktop to draw for the update frame.

how can I make this work properly??