I'm having a bit of a problem with custom associations. Say I have a custom has_one association :latest_comment in model Post

class Post < ActiveRecord::Base
has_many :comments
has_one :latest_comment,
:class_name => "Comment",
:order => "created_at DESC"
end

This code does not seem to create any exceptions, yet when I reference the association :latest_comment from another Controller - like so:

test_comment = Post.latest_comment
(OR)
test_comment_body = Post.latest_comment.body

It gives me the following error:
"undefined method 'latest_comment' for Post:Class"

Shouldn't the association create these methods automatically? What am I doing wrong? Should I specify attr_accessor :latest_comment?
I can't seem to find anything on the internet that refernces this problem. Any of you have any ideas?
Thanks in advance!