Ubuntu 10.04 . When assigning kdm as a default disp man in /etc/X11/default-display-manager to /usr/bin/kdm after successfull login I see that I can't start any X - application from shell term under root account due to empty /root/.Xauthority file and having no entries for root user in xhost. But it was normaly logged in when gdm was a default manager, kdm was launched from within it and root's .Xauthority contained proper display - key entries and xhost had three users: SI:localuser:user, SI:localuser:gdm, SI:localuser:root - X - applications started normaly. So what's the problem, why kdm launched as a default login manager does not add a specific info in .Xauthority and users of X? Thanks.