Ok so mow I tried "GNU Emacs 24.2.1 (i686-pc-linux-gnu, GTK+ Version 3.6.4)
of 2013-04-09 on komainu, modified by Debian" but with the same issue.

here is my .emacs config:

;;
;; ORG Mode
;;
(setq load-path (cons "~/.emacs.d/org-mode/lisp" load-path))
(setq load-path (cons "~/.emacs.d/org-mode/contrib/lisp" load-path))
(require 'org-install)
(require 'ox-rss)
;; Auto load OrgMode with "*.org" files
(add-to-list 'auto-mode-alist '("\\.org\\'" . org-mode))
;;
;; EXPORT
;;
;; Don't use postamble to exported HTML
(setq org-export-html-postamble nil)

;; re-export everything regardless of whether or not it's been modified
(setq org-publish-use-timestamps-flag nil)
;;
;; ORG publish function
;;
(setq org-publish-project-alist
           '(
     ("orgfiles"
               :base-directory "/home/xxxxx/Dropbox/website/src/"
               :base-extension "org"
               :publishing-directory ""/home/xxxxx/Dropbox/website
/public_html/"
       :recursive t
       :html-postamble nil
       :publishing-function org-html-publish-to-html)



              ("images"
               :base-directory ""/home/xxxxx/Dropbox/website/src/"
       :recursive t
               :base-extension "jpg\\|gif\\|png\\|ico"
               :publishing-directory ""/home/xxxxx/Dropbox/website
/public_html/"
               :publishing-function org-publish-attachment)

      ("style"
               :base-directory ""/home/xxxxx/Dropbox/website/src/"
       :recursive t
               :base-extension "js\\|css\\|otf\\|eot\\|svg\\|ttf\\|woff"
               :publishing-directory ""/home/xxxxx/Dropbox/website
/public_html/"
               :publishing-function org-publish-attachment)

       ("sessions"
               :base-directory ""/home/xxxxx/Dropbox/website/src/sessions/"
               :base-extension "css\\|js\\|png"
               :publishing-directory ""/home/xxxxx/Dropbox/website
/public_html/sessions/"
               :publishing-function org-publish-attachment)

       ("rss_posts"
:base-directory ""/home/xxxxx/Dropbox/website/src/posts/"
:base-extension "org"
:rss-image-url "http://xxxx.xxxx.free.fr/fp_icon.png"
:html-link-home "http://xxxx.xxxx.free.fr"
:rss-extension "xml"
:publishing-directory "/home/xxxx/Dropbox/website/public_html/posts/"
:publishing-function (org-rss-publish-to-rss)
:section-numbers nil
:exclude ".*"
:include ("index.org")
:table-of-contents nil)

              ("website" :components ("orgfiles" "images" "style"
"sessions" "rss_posts"))
     )
   )


Any ideas?



2013/7/10 flammable project <flammable.project@gmail.com>

> OK so let's move on Emacs 24...
>
> Thanks for the rapid answer!
>
> Basile
>
>
> 2013/7/10 Bastien <bzg@gnu.org>
>
>> flammable project <flammable.project@gmail.com> writes:
>>
>> > I'm trying to use ox-rss to generate a rss feed but I'm facing an
>> > error :
>> >
>> > let*: Symbol's function definition is void: url-encode-url
>>
>> Mh, yes, `url-encode-url' is not available in Emacs <24.1.
>>
>> I just mentioned this in the comment section, thanks for reporting
>> this problem.
>>
>> 2012-05-09  Chong Yidong  <cyd@gnu.org>
>>
>>         * url-util.el (url-encode-url): New function for URL quoting.
>>
>> --
>>  Bastien
>>
>
>