Diskless client --path config problems

I am setting up diskless clients using KDE in kiosk mode.

It is setup using a read-only NFS root and a read-write tmpfs merged 
into root using UnionFS.  This works well but when I do 'kde-config 
--path config' it shows the path in the Union and on the ro-NFS.  As a 
result I see double-ups all over the place, eg. entries in the menu, icons.

Here are the mounts:
1.1.1.1:/diskless/root on /dev/diskless/roots type nfs 
(ro,v3,rsize=8192,wsize=8192,hard,tcp,nolock,addr=1.1.1.1)
memfs on /dev/diskless/memfs type tmpfs (rw)
unionroot on / type unionfs 
(rw,dirs=/dev/diskless/memfs=rw:/dev/diskless/roots=nfsro,debug=0,delete=whiteout,copyup=preserve)

Here is the 'kde-config --path config' output:
/root/.kde/share/config/:/usr/share/config/:/dev/diskless/roots/usr/share/config/

I have tried setting $KDEDIRS and "dir_config=/usr/share/config/" in 
"kderc" but it always includes both regardless.  If I add something 
obscure to kderc it is "added" to this list. eg.  when "dir_config=/tmp" 
is added i get 
"/root/.kde/share/config/:/usr/share/config/:/dev/diskless/roots/usr/share/config/:/tmp/".

When applying a kiosk profile to a user the kiosk path is added to this 
list. eg. 
"/home/user/.kde/share/config/:/etc/kde-profile/diskless/share/config/:/usr/share/config/:/dev/diskless/roots/usr/share/config/:/tmp/"

Any suggestions how i can get KDE to ignore the "/dev/diskless/roots/" path?

Distro: FC4
KDE: 3.5.1

Yours truly,

Ben