KDEInit could not launch kdesu

[j200303 carido com]

Hi,

I am getting the message "KDEInit could not launch kdesu" when I click on the 
KPPP icon, as a user.

I need to sign as root (su root) in order to launch kppp from xterm or 
konsole. Other solution is to run "kdesu kppp" from kdesktop (Alt+F2).

Everything works fine when I am root. KMail and all the other KDE applications 
work very well, I have this problem with only KPPP.

Any idea?

FYI, I am using RedHat 9.0 with KDE 3.1

Thank you.