Routes problem

Hi i configured custom routes but i got the following errors

Error Number 1:
You have a nil object when you didn't expect it!
The error occurred while evaluating nil.to_sym

17: <td> <%=quipment.numero_activo_fijo%> </td>
18: <td> <%=quipment.direccion_mac%> </td>
19: <td> <%=quipment.numero_serie%> </td>
20: <td><%= link_to 'Show', quipment %></td>
21: <td><%= link_to 'Edit', edit_equipment_path(quipment) %></td>
22: <td><%= link_to 'Destroy', quipment, :confirm => 'Are you
sure?', :method => :delete %></td>
23: </tr>

The thing is that quipment is defined. Here is the source code:

<% for quipment in @equipments %>
  <tr>
    <td> <%=quipment.numero_activo_fijo%> </td>
    <td> <%=quipment.direccion_mac%> </td>
    <td> <%=quipment.numero_serie%> </td>
    <td><%= link_to 'Show', quipment %></td>
    <td><%= link_to 'Edit', edit_equipment_path(quipment) %></td>
    <td><%= link_to 'Destroy', quipment, :confirm => 'Are you sure?',
:method => :delete %></td>
  </tr>
<% end %>

Now if I remove the line 20, 21, 22 from the file i got error number 2
Error number 2:

undefined local variable or method `new_equipment_path' for
#<ActionView::Base:0x2aaaae5c3bf8>

Here is the route for equipments

  map.resources :equipment,
                :singular=>:equipment_instance,
                :collection =>{
                         :add_equipment => :get,
                         :index => :get
                }

if i remove the :singular => xxx line the problem is solved but the new
methods give me errors

Thank you very much for the help