show-wspace.el fontlock problem

[jeff-xemacs at delphioutpost.com]

   From: Neal Becker <ndbecker2 at gmail.com>
   Date: Mon, 25 Feb 2008 08:58:37 -0500
   
   I'm trying out show-wspace.el:
   
   http://www.emacswiki.org/cgi-bin/wiki/show-wspace.el
   
   Sort of works, but I'm getting millions of messages:
   Fontifying region...(invalid-function 0)
   
   Strangely, setting debug-on-error doesn't seem to trap the message.
   
   I'm thinking this should be simple to debug.  At the end of show-wspace.el
   there are several font-lock-add-keywords that I was thinking might be the
   cause, but I don't see it (I'm just going from the font-lock-add-keywords
   doc, I don't have any experience with this).

When I compile (in 21.4.18) this file I get 

Compiling file /home/jeff/.xemacs/lisp/wiki/show-wspace.el at Mon Feb 25 15:54:28 2008
  ** the function font-lock-add-keywords is not known to be defined.

So, I suspect you have a broken font-lock-add-keywords
that added something odd to font-lock-keywords.
-jeff