Pagination is ignoring my RESTful routes?

My routes for parent = project and child = portal looks like this:
  map.resources :projects do |projects|
    projects.resources :portals, :name_prefix => "project_"
  end

In my portals=index I have the following Pagination code that's always
worked for me.
    @portal_pages = Paginator.new self, @project.portals.count, 3,
params[:page]
    @portals = @project.portals.find :all,
       :order => 'description',
       :limit => @portal_pages.items_per_page,
       :offset => @portal_pages.current.offset

The code at the bottom of the portal.index view is
<%= link_to 'Previous page', { :page =>
@portal_pages.current.previous } if @portal_pages.current.previous %>
<%= link_to 'Next page', { :page => @portal_pages.current.next } if
@portal_pages.current.next %>

My index view displays the first page correctly displaying this route:
http://localhost:3005/projects/1/portals
When I click the NEXT button a NON-nested route is called that
'coughs' as the parent PROJECT.id is nowhere to be found (as shown)
http://localhost:3005/portals?page=2.

Shouldn't the route that is built be http://localhost:3005/projects/1/portals?page=2.
The error displayed = Error = ActiveRecord::RecordNotFound in
PortalsController#index
Couldn't find Project without an ID
Is there a special Paginator object for nested RESTful routes?
Thanks,
David