CakePHP Auth Component and Paypal IPN Plugin

I'm trying to set up the paypal_ipn plugin for cakephp. It has admin routes for the backend stuff, but I'm having trouble setting up the auth component.

The plugin installation says I need to be 'logged in as an admin using the auth component'. I assume there is no way of accessing the admin functions without using auth? (just for dev).

If I enter /admin/paypal_ipn I get a missing controller error. I've spent a while playing with auth and the plugin routes, but I can't get it to play. I dont know if I'm overthinking things.

Can anyone offer any pointers? Thanks. I can supply code if it helps.