I tried to activate the graphic logon screen but after I type my login user and
password I get a small windows with the following message:

choose SessionList Widget

and a Cancel button.  The three other buttons are grayed out.

I click on the cancel button and I get back to the logon window.  There is no
other option to choose and I end up on an endless loop.

What can be the problem?  Is this a missconfiguration in XFree86?

Regards
Fernando

-- 
A lot of people approach risk as if it's the enemy when it's really fortune's
accomplice. (Sting)
Choose well. Your choice is brief, and yet endless. (Goethe)