ApiInfusionsoft error "undefined method `api_perform' for nil:NilClass"

api_infusionsoft.rb

# config/initializers/api_infusionsoft.rb
# actual file contains reall app and key values.
ApiInfusionsoft.set_account_apiconn("MYAPP.infusionsoft.com", "MYKEY")

UsersController.rb

class UsersController < ApplicationController
  
  include ApiInfusionsoft
  
  def index
    @users = User.all
    
    infuser = api_data_query(:Contact,1,0,{:Id=>3674}, ["Id", "FirstName", "LastName"])
    print "\n infuser #{infuser.inspect}"

    respond_to do |format|
      format.html # index.html.erb
      format.xml  { render :xml => @users }
    end
  end
  
  # other methods rm'd for this example.

end

Hello.. I'll check it out, and respond later this evening.