title: Delayed_job : NoMethodError: undefined method `my_method_without_delay'
body: <p>Using rails 2.3.11 and delayed_job 2.0.4 as a gem I get an error when using <code>handle_asynchronously</code> :</p>
  
  <p>In my ActionMailer model, I delcared my_method and added ' handle_asynchronously :my_method' right after the declaration :</p>
  
  <pre><code>class MailSender &lt; ActionMailer::Base
      def my_method
          ...
      end
      handle_asynchronously :my_method
  end
  </code></pre>
  
  <p>When calling <code>MailSender.deliver_my_method</code> the task is correctly added to the queue. But when trying to process it, it fails with the error message :</p>
  
  <pre><code>undefined method `rappel_email_without_delay' for #&lt;YAML::Object:0x1034b85f8&gt;
  </code></pre>
  
  <p>Delaying with <code>MailSender.delay.deliver_my_method</code> is working and the task correctly processed - But i'd rather use <code>handle_asynchronously</code> un my model to ensure mail are always sent in the background...</p>