Rails - Dec 2005 - ferret setup

Hi there,

Is there any setup involved in getting ferret in a rails application ?
As soon as I include a reference to ferret in one of my application
controllers:

require "ferret"
include Ferret

even though I am not including any code related to the ferret module,
i am getting the following exception, that has to do with paginations,
undefined method `count'' for Ferret::Document:Module