Is there any way to know which files Rails is opening when doing I18n?

I'm having trouble with translations (I18n) in Rails 3. There are a couple of words that I can't realize from where Rails/I18n is trying to read the translation.

My form has a simple_form inside a custom_form. Something like this:

<%= custom_form_for(@prospect) do |f| %>
  <div class="row-fluid">
    <div class="span4">
      <%= f.input :usuario_id, :wrapper => :prepend, :label => false do %>
        <%= f.label :usuario_id, :class => "add-on", :required => false %>
        <%= f.input_field :usuario_id, :collection => @usuarios %>
      <% end %>
    </div>
    <%= f.simple_fields_for :crm_dados_entidade_attributes do |cde| %>
      <div class="span4">
        <%= cde.input :origem_lead_id, :wrapper => :prepend, :label => false do %>
          <%= cde.label :origem_lead_id, :class => "add-on", :required => false %>
          <%= cde.input_field :origem_lead_id, :collection => @origem_leads %>
        <% end %>
      </div>
    <% end -%>
  </div>
<% end -%>

I have translation files for each model. For example: prospects.yml, leads.yml, and son on...

My problem is that the fields in the custom_form_for are translated correctly, but the fields in the simple_fields_for are not translated. Actually, the output for origem_lead_id is: 'Origem lead', when my translation file is like this:

pt-BR:
  activerecord:
    models:
      'crm/crm_dados_entidades': 'Pessoa'
    attributes:
      'crm/crm_dados_entidade':
        origem_lead_id: 'Origem do Lead'
        origem_lead: 'Origem do Lead'

I've tried to put this code in several files and in different ways, like (prospects.yml, crm_dados_entidades.yml), attributes for ( 'crm/crm_dados_entidade', 'crm/prospects').

Nothing seems to work. So, my question is: Is there anyway to track where Rails/I18n is looking for the translation?