permissions?

[Ken Moffat]

I installed xfce4 using the 'update-xfce' script, with the '-A' switch, 
and can run it using 'startxfce4' as root, and as root from gdm, but 
when I try as a user to run it, I get a 'user does not have permission 
to run X' error.

I'm running libranet linux (debian) and I ran the script and 
successfully ran xfce4 on my old install of libranet, on which I had 
already installed a .deb of xfce4.

Is there a file I need to change permissions on? Clues?