Emacs-W3m bug

["Lazycat Manatee" <lazycat.manatee@xxxxxxxxx>]

Hi!
I use Emacs-W3m (version: 1.5) in Emacs CVS (version: 23.0.60.2)
I test one bug about Emacs-W3m coding, and details is:

I'm write a function that can search keyword in "Google Blog Search":

--------------------> function start <--------------------
(defun w3m-search-google-blog (what)
  "Use Google blog search for WHAT."
  (interactive "sGoogle Blog: ")
  (w3m-goto-url-new-session (concat
"http://blogsearch.google.cn/blogsearch?hl=zh-CN&ie=UTF-8&q=";
				    (w3m-url-encode-string what))))
--------------------> function end <------------------------

then, i use it search, example, "ÈÕ±¾".
The coding of first page is right, and then if i view second page or
back pages is wrong.
And the coding of url (Location position of w3m) is auto became
"GB2312", and not "UTF-8".
I use Firefox search in "Google Blog Search", the coding of all pages is right.

And my setup about coding of Emacs-W3m is blow:
--------------> coding setup start <-------------
(setq w3m-default-coding-system 'utf-8)
(setq w3m-coding-system 'utf-8)		
(setq w3m-file-coding-system 'utf-8)
(setq w3m-file-name-coding-system 'utf-8)
(setq w3m-terminal-coding-system 'utf-8)
--------------> coding setup end <-----------------

So, is my setup about Emacs-W3m coding is wrong? or is a bug of Emacs-W3m?

Thank you very much!  ^_^