If you login as a non-root user to konsole and do 'sudo -s' to root (if you have this set up in /etc/sudoers,) then unlike the plain console, konsole does not display a root prompt. Also after you do this it actually does not let you use all root commands, though 'whoami' shows you are root.

That is because sudo does not change your environment correctly.

Try: "sudo su -" instead.

Also "sudo -i"