Fluxbox doesn't start any more on SuSE

Hi all!
I run SuSE linux 9.3
After running happily with Fluxbox for some weeks I had to update the
kernel and other packages (which I don't exactly remember), the result?
I cannot login any more into neither fluxbox nor blackbox.
I tried reinstalling the program without success.
It's strange because at login screen on the menu there is listed
"fluxbox" but when I try to login the computer freezes (although mouse
pointer still moves) without loading the window manager. To regain
control I have to reset X (ctrl+alt+backspace).
I really can't figure out what has gone wrong... Now only KDE and
Failsafe work!
Have you any Idea?
Thanks all.
alde