With rails 2.2.2 this code :
<%= render :partial => 'order', :collections => @orders %>
with partial _order.html.erb : <% div_for order do %> <%= order.title %><br/> <% end %>
Called id for nil, which would mistakenly be 4 -- if you really wanted the id of nil, use object_id
while this peace of code work fine : <% @orders.each do |order| %> <%= render :partial => 'order', :locals => { :order => order } %> <% end %>
