can't connect to ANY desktop !

[moi 1392 <moi1392@gmail.com>]

This morning I could start a desktop session (kde), I apt-get upgrade,
and after shutting down and up my computer I was unable to start any
desktop session !

I tried kde / gnome / enlightenment with xdm / kdm / gdm and startx,
with my account, root and an account that I just created to test !!

Each time, after I enter my password and validate, X restart and
reprompt x/g/kdm or I return under my VT.

I can't get any useful message from Xorg.0.log, /var/log/syslog, dmesg
and /var/log/daemon.log.

In gdm, I get this error message :

/etc/X11/gdm/PreSession/Default: Registering your session with wtmp and utmp
/etc/X11/gdm/PreSession/Default: running: /usr/X11R6/bin/sessreg -a -w
var/log/wtmp -u /var/run/utmp -x "/var/lib/gdm/:0.Xservers" -h "" -l
":0" "moi"
/etc/X11/gdm/Xsession: Beginning session setup...

And that's all...

Someone have an idea or an advice ? I'm really clueless !!