Installed FC3 with just XFree86 and XFCE as the window manager.
On the default login screen, when you log in you get TWM by default!
Even though XFCE is installed.
XFree86 is not even part of Fedora Core since Fedora Core 1.
The supported desktops are GNOME and KDE. twm is a failsafe
fallback for if problems occur only.
You need to manually set up xfce yourself by editing user startup
files such as .xinitrc.
Closing as "NOTABUG"
Sorry I called Xorg XFree86, it is Xorg then.
Your advice about .xinitrc in FC3 is misguided. You can use the
switchdesk or switchdesk-gui to change to XFCE.
XFCE is one of the 3 Window Mangers presented on the installer in FC3.
When I install that from that menu it should be the default window
manager if you don't have Gnome or KDE installed.