minor

app/models/member.rb

@@ -1,6 +1,7 @@
 include ApplicationHelper
 class Member
   include Mongoid::Document
+  include Mongoid::Timestamps
   referenced_in :user
   referenced_in :project
   after_destroy :destroy_project_rate

app/models/project_rate.rb

@@ -1,3 +1,4 @@
 class ProjectRate < Rate
   referenced_in :project
+  referenced_in :user
 end

app/models/rate.rb

@@ -1,5 +1,4 @@
 class Rate
   include Mongoid::Document
-  field :amount
-  referenced_in :user
+  field :amount, :type => Integer
 end

app/models/user.rb

@@ -20,7 +20,7 @@ def projects
   end
   def rate_for(object)
     if object.instance_of? Project
-      rates.where(:project_id => object.id).first
+      rates.where(:project_id => object.id).desc(:_id).first
     end
   end
   def tasks_for_dates(start_date, end_date)