TeX-comment-or-uncomment-region args out of range

Emacs-21.4 and AUCTeX commenting leads to
args out of range.

This problem is reported by Ikumi Keita.

Trigger is as followed 
(1) emacs -q
(2) (require 'tex-site)
(3) (transient-mark-mode t)
(4) (find-file "foo.tex")
>> foo.tex <<
\documentclass{article}
\begin{document}

\end{document}
<<---------->>
(5) M-x font-lock-mode
(6) set point at the beginning of line of `\begin{document}'
(7) C-SPC (set mark)
(8) C-n (next-line)
(9) C-c ; (TeX-comment-or-uncomment-region)

debugger message is as followed.

Debugger entered--Lisp error: (args-out-of-range 24 25)
  put-text-property(24 25 fontified nil)
  jit-lock-after-change(25 25 0)
  comment-region-internal(25 41 "% " nil nil nil nil nil nil)
  comment-region(25 42 nil)
  TeX-comment-region(25 42 nil)
  TeX-comment-or-uncomment-region(25 42 nil)
  call-interactively(TeX-comment-or-uncomment-region)


Emacs  : GNU Emacs 21.4.1 (i686-pc-linux-gnu, X toolkit, Xaw3d scroll bars)
 of 2005-02-09 on h230.90.226.10.30007.vlan.kuins.net
Package: AUCTeX CVS-5.485 (2005-02-12)

current state:
==============
(setq
 window-system 'x
 LaTeX-version "2e"
 TeX-style-path '("style/" "auto/"
		  "/usr/local/share/emacs/site-lisp/auctex/style/"
		  "/usr/local/var/auctex/")
 TeX-auto-save nil
 TeX-parse-self nil
 TeX-master t
 )

---
email: [email protected]
Name:: Masayuki Ataka // (Japan)