Desktop switcher

[Matt Soccio]

I just built a new debian box and installed xfce 4.0.1 from source. 
Previously, when I used xfce4, the desktop switcher would display
mini-windows for all of the windows on my desktops.  This new install
just displays the name of the desktop with the gtk-theme decoration.

Are the mini-windows an xfce function or gtk?  Is there a backend
program I need running to get the mini-windows again?

Thanks

Matt