When I start xfce using xfwm4 and then run "xmonad --replace" from a
terminal, I practically arrive at my dream desktop. However, when I
configure xfce to autostart xmonad, I can briefly see the xfce4 panel
flash up and then immediately disappear. xmonad just leaves an empty
space where the panel is supposed to be. mod-b toggles the empty space
but does not show the panel. The default configuraiton of Lubuntu is to
have a single panel at the top of the screen.