Lost in nested routes

I cannot edit records for nested model. I have two models... Document and Contentitem. Document has_many Contentitems.

The following link on the Document show page...

<%= link_to 'Edit', [@document, content], :method => :edit %>

Causes the following error...

No route matches "/documents/1/contentitems/9"

This is what I have... any ideas?

========= routes.rb ==============

Dg::Application.routes.draw do

  root :to => "documents#index"

  resources :templategroups do      resources :templateitems   end

  resources :documents do     resources :contentitems     member do         put 'insert_into'         put 'sort'     end   end end

========== contentitems_controller =======

class ContentitemsController < ApplicationController   before_filter :load_document

  ...

  def edit      @contentitem = @document.contentitems.find(params[:contentitem])   end

  ...

  private     def load_document         @document = Document.find(params[:document_id])     end

end