[SLUG] Newbie root problems

[Josh Shone <josh.shone@xxxxxxxxxxxxxx>]

I want log in as root. Discovered that you can allow for this in KDE by 
adjusting "AllowRootLogin=true" in the file kdmrc. Cannot do this 
however, because I can't log in as root... So I go to the terminal and I 
say:

   su
   (My root password)

and tada:

   su: Authentication Failure

I type my correct password, in other parts of KDE (e.g. Adept) it works 
fine. (Typing "su root" or using "su -" and so forth makes no diff.) 
Googling on this matter brings nothing. Sorry for the apparently stupid 
question so very soon after my last...