> I do have a problem though... when I 'su' as a regular user > i do not have access to the local Xserver to run X-programs.
Check /etc/kde2/kdm/Xservers. If you see "-nolisten tcp" on the server line then you have TCP/IP access to the Xserver disabled. This became the default some time recently; I had the same problem also. Try deleting "-nolisten tcp" and see if things work for you. Ben.
