Having problem with ckeditor rubygem

I've installed the ckeditor gem. I'm running rails 2.8.3 and have
followed the steps in the README file for the gem. Everything seems to
run without error through the <%= javascript_include_tag :ckeditor %> -
except that to make it work I have to replace :ckeditor with "ckeditor".

When I try to use the helper: <%= ckeditor_textarea("object", "field",
:width => '100%', :height => '200px') %> (I'm copying it verbatim from
the documentation and will tailor it after I have it generating the
editor), it fails with the following error message:

   undefined method `ckeditor_textarea' for

Obviously, I'm omitting something I need to do. Would someone be so kind
as to let me know what I'm missing?

Thanks much.