[O] Capture aborts after selecting template

[Felix]

I am using GNU Emacs 23.1.1 with org-mode version 7.7. I want to use C-c c t to
capture a task and send it to ~/todo.org as defined in the org-capture-template
 below. On pressing C-c c, the Org Select buffer opens but when I hit t, I get
the error message "Capture abort: (void-function nil)" and nothing gets written
to todo.org. The relevant lines from my
.emacs and a backtrace from uncompiled code are shown below.  Please help me fix
this.  

.EMACS
(define-key global-map "\C-cc" 'org-capture)
(setq org-directory "~/")

(setq org-capture-templates
      (quote 
      (("t" "Todo" entry (file+headline "~/todo.org" "Tasks")
             "* TODO %?\n  %i\n  %a")
        ("j" "Journal" entry (file+datetree "~/journal.org")
             "* %?\nEntered on %U\n  %i\n  %a"))))

BACKTRACE (Although I followed the instructions carefully, my backtrace still
has some byte code that I couldn't paste here.)
Debugger entered--Lisp error: (void-function nil)
  nil()
  run-hooks(text-mode-hook outline-mode-hook org-mode-hook)
  apply(run-hooks (text-mode-hook outline-mode-hook org-mode-hook))
  run-mode-hooks(org-mode-hook)
  org-mode()
  set-auto-mode-0(org-mode nil)
  byte-code(..."*Ň" [modes mode --dolist-tail-- done keep-mode-if-same nil
functionp message "Ignoring unknown mode `%s'" t set-auto-mode-0 throw nop] 4)
  set-auto-mode()
  normal-mode(t)
  after-find-file(nil t)
  find-file-noselect-1(#<buffer todo.org> "~/todo.org" nil nil "~/todo.org"
(305483 2049))
  find-file-noselect("/home/vadmin/todo.org")
  org-capture-target-buffer("~/todo.org")
  org-capture-set-target-location()
  org-capture(nil)
  call-interactively(org-capture nil nil)