validation not working properly with nested form

Hi all,

I have two class class Person     include MongoMapper::Document     one :address     validates_associated :address

   ... validates for keys    ... other keys end

class Address     include MongoMapper::EmbeddedDocument     belongs_to :person

   ... validates for keys    ... other keys end

And i have the following in my view <%= form_for(@person) do |f| %>

   .... fields for person

      <%= f.fields_for :address do |address_form| %>           ... fields for address       <% end %> <% end %>

when i click submit button, validation is working for both class, however only fields in Person class get highlighted, fields for Address class will NOT highlight.

how can i fixed this?

Thanks