XServer (i'm told) only runs on terminal 7 - press alt+F7 and try starting X again..
Alternatively, instead of using F1, while in X, bring up a shell, become root and type init 3.
) edit /etc/inittab and make the default runlevel 3
Alternatively, in GDM, or KDM, select Fluxbox rather than starting it manually.
to start gnome once in init (boot) level 3, become root, type gdm or kdm (which ever is your display manager, could be xdm also ... careful with that, in my experience it defaults to qwertz keyboard map, which could be bad if your password involves a z or y).