Show desktop icon non shown anymore

[Bob Alexander <bob@ngi.it>]

On Gnome desktop's bottom panel I have a "Hide all windows and show 
desktop" button which works but it's icon disappeared and is now a red 
cross on a white page.

Adding the same "applet"with add to panel shows a list and also there 
the show desktop has no icon.

Where is this resource held/described ?

How can I reinstate it ?

bob@t40:~$ ls -l /usr/share/pixmaps/gnome-ccde*
-rw-r--r--  1 root root 3002 2005-03-04 19:34 
/usr/share/pixmaps/gnome-ccdesktop.png

and

bob@t40:~$ ls -l /usr/share/pixmaps/other/GNOME-CCDesktop.png
-rw-r--r--  1 root root 1763 2001-09-24 18:58 
/usr/share/pixmaps/other/GNOME-CCDesktop.png

I can see them in konqueror and/or gimp as 48x48 pixmaps.

Right clicking on the "show desktop does not bring up a "Properties" 
dialog in which I had hoped to find the icon for the appl.

Any ideas ?

Thanks a lot.

Bob