[O] getting started with publishing

[Kevin Buchs]

I tried to get going with publishing to html, starting from this guide:
http://orgmode.org/worg/org-tutorials/org-publish-html-tutorial.html . I am
running emails 24.3 on Windows with the latest ELPA org mode. I am getting
a complaint when I try to publish:

org-refresh-category-properties: Invalid function:
org-with-silent-modifications

Here is my setup

(require 'org-publish)
(setq org-publish-project-alist
   '(
      ("RCS-Notes"
  :publishing-function org-html-publish-to-html
          :base-directory "I:/SHARED/KevinBuchs/org"
          :publishing-directory "I:/SHARED/KevinBuchs/html"
  :base-extension "org"
  :recursive t ; include subdirs
  :headline-levels 4  ; default for this project
  :preparation-function nil ; functions called prior to publishing
  :completion-function nil ; functions called after publishing
  :auto-preamble t)
      ("RCS-Static"
  :publishing-function org-publish-attachment
          :base-directory "I:/SHARED/KevinBuchs/org"
          :publishing-directory "I:/SHARED/KevinBuchs/html"
  :base-extension "css\\|js\\|png\\|jpg\\|gif\\|pdf\\|mp3\\|swf"
  :recursive t) ; include subdirs
      ("RCS"
  :components ("RCS-Notes" "RCS-Static")) ))

What might I be missing?

Thanks
Kevin Buchs