Ecco il risultato:

knoppino@Maurizio:~$ su
Password:
root@Maurizio:/home/knoppino# krandrtray
Creating link /root/.kde/socket-Maurizio.
Created link from "/root/.kde/socket-Maurizio" to "/tmp/ksocket-root"
_kde_IceTransmkdir: Owner of /tmp/.ICE-unix should be set to root
/usr/X11R6/bin/iceauth: creating new authority file /root/.ICEauthority
QPixmap: Cannot create a QPixmap when no GUI is being used
QPixmap: Cannot create a QPixmap when no GUI is being used
Creating link /root/.kde/tmp-Maurizio.
Created link from "/root/.kde/tmp-Maurizio" to "/tmp/kde-root"
Xlib: connection to ":0.0" refused by server
Xlib: No protocol specified

kded: cannot connect to X server :0.0
DCOP aborting call from 'anonymous-1216' to 'kded'
kded: ERROR: Communication problem with kded, it probably crashed.
Xlib: connection to ":0.0" refused by server
Xlib: No protocol specified

kdeinit: Can't connect to the X Server.
kdeinit: Might not terminate at end of session.
Xlib: connection to ":0.0" refused by server
Xlib: No protocol specified

krandrtray: cannot connect to X server :0.0
krandr: ERROR: KUniqueApplication: Registering failed!
krandr: ERROR: Communication problem with krandr, it probably crashed.
root@Maurizio:/home/knoppino# Mutex destroy failure: Dispositivo o risorsa occupata
E mo'?
La knoppix l'ho installata!