Rails 3.1 - Cant edit and create on same partial - nested resources - ruby-on-rails

Question

I have a admin section and inside the admin i have, Finalist and Images.
Im using, ruby 1.8.7-p249 and Rails 3.1.2
# model image.rb
class Admin::Image < ActiveRecord::Base
belongs_to :finalist
...
end
# model finalist.rb
class Admin::Image < ActiveRecord::Base
has_many :images
...
end
My ImagesController:
def new
#admin_finalist = Admin::Finalist.find(params[:finalist_id])
#admin_image = #admin_finalist.images.build
respond_to do |format|
format.html # new.html.erb
format.json { render :json => #admin_image }
end
end
def edit
#admin_finalist = Admin::Finalist.find(params[:finalist_id])
#admin_image = #admin_finalist.images.find(params[:id])
end
def create
#admin_finalist = Admin::Finalist.find(params[:finalist_id])
#admin_image = #admin_finalist.images.new(params[:admin_image])
respond_to do |format|
if #admin_image.save
format.html { redirect_to admin_finalist_images_path(#admin_finalist) }
format.json { render :json => #admin_image, :status => :created, :location => #admin_image }
else
format.html { render :action => "new" }
format.json { render :json => #admin_image.errors, :status => :unprocessable_entity }
end
end
end
def update
#admin_finalist = Admin::Finalist.find(params[:finalist_id])
#admin_image = #admin_finalist.images.find(params[:id])
respond_to do |format|
if #admin_image.update_attributes(params[:admin_image])
format.html { redirect_to admin_finalist_images_path(#admin_finalist) }
format.json { head :ok }
else
format.html { render :action => "edit" }
format.json { render :json => #admin_image.errors, :status => :unprocessable_entity }
end
end
end
And my Images _form.html.erb:
<%= form_for([#admin_finalist, #admin_image]) do |f| %>
<% if #admin_image.errors.any? %>
<div id="error_explanation">
<h2><%= pluralize(#admin_image.errors.count, "error") %> prohibited this admin_image from being saved:</h2>
<ul>
<% #admin_image.errors.full_messages.each do |msg| %>
<li><%= msg %></li>
<% end %>
</ul>
</div>
<% end %>
<div class="field">
<%= f.label :file %>
<%= f.file_field :file %>
</div>
<%- unless #admin_image.new_record? || !#admin_image.file? -%>
<div class="field">
<%= f.label :remove_file, "Remover?" %>
<%= f.check_box :remove_file %>
</div>
<%- end -%>
<div class="field">
<%= f.label :url %>
<%= f.text_field :url, :placeholder => "http://" %>
</div>
<div class="field">
<%= f.label :title %>
<%= f.text_field :title %>
</div>
<div class="actions">
<%= image_submit_tag("button/save.png") %>
<%= link_to image_tag("button/back.png"), admin_finalist_images_path %>
</div>
<% end %>
Everything seems perfect, but im getting this error when im trying to add an image to finalist at admin/finalists/1/images/new.
Showing .../app/views/admin/images/_form.html.erb where line #5 raised:
undefined method `admin_finalist_admin_images_path' for #<#<Class:0x102da0068>:0x102d9a870>
So, i tryed to tell rails to use a particular url:
<%= form_for([#admin_finalist, #admin_image], :url => admin_finalist_image_path(#admin_finalist.id, #admin_image)) do |f| %>
Saddly, this work only for editing. When i try to edit i get this error message:
No route matches {:controller=>"admin/images", :finalist_id=>1, :id=>nil, :action=>"show"}
And if i wanna create i need to do:
<%= form_for([#admin_finalist, #admin_image], :url => admin_finalist_images_path) do |f| %>
And if i try to edit i get this message:
No route matches [PUT] "/admin/finalists/1/images"
I dont know what to do... I tried everything without success, if anyone can help me would be much appreciated.
EDIT
The problem was that my models was namespaced. So, i rewrite all the app to fix this, and thats running normally.
[]`s