Do you have a root password- or not?
If you don't, then "it does nothing" translates to changing
[sillycat@mycomputer ~]$
to
[root@mycomputer ~]#
...which is perfectly adequate!
What happens if you press alt+F2 and then enter
CODE
kdesu konsole
If you don't have a root password (which BTW is a very bad idea), then again "nothing will happen"- you will just have a root console handy...