message mode loses highlighting

[Ted Zlatanov <tzz@lifelogs.com>]

I have the following in my .emacs:

(defface font-lock-empty-line-face
  '((t (:height 80 :inherit default)))
  "Font Lock mode face used for blank lines."
  :group 'font-lock-highlighting-faces)

(defvar font-lock-empty-line 'font-lock-empty-line-face
  "Face name to use for blank lines.")


(defun tzz-highlighting-install ()
  (interactive)
  (font-lock-mode t)
  (font-lock-add-keywords
   nil 
   `(("^\\([^-A-Za-z0-9]+\\)$" (0 'font-lock-empty-line-face))
     ("\n" (0 'font-lock-empty-line-face))
     ("\\(FIXME\\|TODO\\)" (1 'font-lock-warning-face prepend)))))

(dolist  (hook '(emacs-lisp-mode-hook
		 cperl-mode-hook
		 shell-mode-hook
		 text-mode-hook
		 change-log-mode-hook
		 makefile-mode-hook
		 texinfo-mode-hook))
  (add-hook hook 'tzz-highlighting-install))

And it shouldn't interfere with message mode, but it does.  When I
compose a message, all the highlighting is gone.

Can anyone suggest a fix?  I'm pretty sure this is the problem, since
it's the only thing I've changed in my .emacs and things work fine
without it.

Thanks
Ted