Liverails tutorial | Error

Hello all,

I followed the liverails tutorial and made a facebook application (the social recipe application). Up till the point where we run our application using an IFrame, my application works fine, but when we change our application settings to use FBML and deploy it to a live ip machine, I get an error

Received HTTP error code 422

when I send a hit to

I have rails version 2.0.1. Any help in this regard will be highly appreciated