Newbie: Help with wiki IMAP example

Hi,
I implemented the IMAP example at the bottom of:
http://wiki.rubyonrails.com/rails/pages/HowToReceiveEmailsWithActionMailer

The receiver app (inbox.rb) works fine when I run it against my mail
server with the following line commented out: MailReader.receive(to,
body)

But when I uncomment that line I get error:

inbox.rb:15 uninitialized constant MailReader (NameError)

There is of course app/models/mail_reader.rb running in my rails app.

How do I get the mail receiver app to know about the MailReader model?

I start the rails app with: ruby script/server -p 80

In another cmd window I then run the receiver app with ruby
script/inbox.rb

Any help appreciated.
Regards,
Eric