C-c a t doesn't give yield list of all TODO items

["Christopher W. Ryan" <cryan@binghamton.edu>]

I'm running GNU Emacs 23.1.1 (i486-pc-linux-gnu, GTK+ Version 2.20.1)
  of 2011-03-04 on palmer, modified by Debian, on Ubuntu 10.04 LTS. 
Org-mode version 7.6.

The online Org-mode manual reads:

"10.3.2 The global TODO list

"The global TODO list contains all unfinished TODO items formatted and 
collected into a single place.

"C-c a t     (org-todo-list)
     "Show the global TODO list. "

But when I try to type C-c a

I only get that far, and emacs tells me, "C-c a is undefined"

There is a drop-down menu item under the Org item, called "Agenda 
Command..." which offers me lettered choices, and t will list all TODO 
entries. But what is the keyboard shortcut, if not C-a a t ?

Thanks.

--Chris Ryan

PS: in case it is relevant, my .emacs file, rather a short one, looks 
like this:

;;(load-file "~/.emacs.d/color-theme/themes/color-theme-subdued.el")
;;(color-theme-subdued)

(require 'color-theme)
(color-theme-parus)
(custom-set-variables
   ;; custom-set-variables was added by Custom.
   ;; If you edit it by hand, you could mess it up, so be careful.
   ;; Your init file should contain only one such instance.
   ;; If there is more than one, they won't work right.
  '(org-agenda-files (quote ("~/DATA/BookIdeas.org" "~/orgjunk.org"))))
(custom-set-faces
   ;; custom-set-faces was added by Custom.
   ;; If you edit it by hand, you could mess it up, so be careful.
   ;; Your init file should contain only one such instance.
   ;; If there is more than one, they won't work right.
  )

;; don't make back-up files
(setq make-backup-files nil)

;; single space between sentences
(setq sentence-end-double-space nil)

;; active Babel languages
(org-babel-do-load-languages
  'org-babel-load-languages
  '((R . t)
    ))