Can't Get Org-Drill to Work

[M. P.]

I am trying to install org-drip. I have org and org-contrib installed through 
Elpa. The Problem has something to do with the line (require `org-drill. When I 
try to run this config I get

Warning (initialization): An error occurred while loading ‘/Users/m.r.p/.emacs’:

Symbol's function definition is void: copy-list

The documentation tells me to You will also need to make sure that Org's 
"contrib/lisp" directory is in the emacs load-path. How do I do this? 


                             Here is my config file.
;; Added by Package.el.  This must come before configurations of
;; installed packages.  Don't delete this line.  If you don't want it,
;; just comment it out by adding a semicolon to the start of the line.
;; You may delete these explanatory comments.
(package-initialize)
(require 'org-drill)
(require 'package)
(add-to-list 'package-archives '("org" . "http://orgmode.org/elpa/";) t)

Any Ideas would be most appreciated.