don't update timestamps in the migration

db/migrate/20110527135552_photo_status_message_association_on_guid.rb

@@ -7,6 +7,7 @@ class PhotoStatusMessageAssociationOnGuid < ActiveRecord::Migration
   def self.up
     add_column :posts, :status_message_guid, :string
     
+    ActiveRecord::Base.record_timestamps = false
     photos = Post.where(Post.arel_table[:status_message_id].not_eq(nil).and(Post.arel_table[:type].eq('Photo')))
     photos.each do |photo|
       if Post.where(:id => photo.status_message_id).exists?
@@ -25,6 +26,7 @@ class PhotoStatusMessageAssociationOnGuid < ActiveRecord::Migration
   def self.down
     add_column :posts, :status_message_id, :integer
     
+    ActiveRecord::Base.record_timestamps = false
     photos = Post.where(Post.arel_table[:status_message_guid].not_eq(nil).and(Post.arel_table[:type].eq('Photo')))
     photos.each do |photo|
       if Post.where(:guid => photo.status_message_guid).exists?