when adding and changing to fvwm2 in the list of window managers using the gnome-control-center, the main gnome panel bar is displayed inconsistently... usually, the top left desktop (desktop 1) has the panel bar correctly, but the other three either don't have the panel bar or it doesn't show correctly...
fvwm2 does not understand GNOME virtual desktops. You cannot use fvwm2 as your window manager if you want to use GNOME-style virtual desktops.