exists? with default_scope error (AR >= 2.3.9)

exists_with_scope.log

D, [2010-10-13T12:06:16.254575 #16142] DEBUG -- :   SQL (0.3ms)  select sqlite_version(*)
D, [2010-10-13T12:06:16.255374 #16142] DEBUG -- :   SQL (0.5ms)  CREATE TABLE "widgets" ("id" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, "accessory_id" integer) 
D, [2010-10-13T12:06:16.255771 #16142] DEBUG -- :   SQL (0.1ms)  CREATE TABLE "accessories" ("id" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL) 
D, [2010-10-13T12:06:16.271467 #16142] DEBUG -- :   SQL (0.1ms)   SELECT name
 FROM sqlite_master
 WHERE type = 'table' AND NOT name = 'sqlite_sequence'

D, [2010-10-13T12:06:16.275491 #16142] DEBUG -- :   SQL (0.1ms)  INSERT INTO "accessories" VALUES(NULL)
D, [2010-10-13T12:06:16.281336 #16142] DEBUG -- :   SQL (0.1ms)  INSERT INTO "widgets" ("accessory_id") VALUES (1)
D, [2010-10-13T12:06:16.286909 #16142] DEBUG -- :   Widget Load (0.1ms)  SELECT "widgets"."id" FROM "widgets" WHERE ("widgets"."accessory_id" = 1) LIMIT 1

exists_with_scope.rb

gem 'activerecord', '3.0.0'

require 'active_record'
require 'logger'
require 'pp'

ActiveRecord::Base.logger = Logger.new('exists_with_scope.log')
ActiveRecord::Base.establish_connection(:adapter => 'sqlite3', :database => ':memory:')

ActiveRecord::Base.connection.create_table :widgets do |t|
  t.references :accessory
end

ActiveRecord::Base.connection.create_table :accessories do |t|
end

class Widget < ActiveRecord::Base
  belongs_to :accessory

  default_scope :include => :accessory
end

class Accessory < ActiveRecord::Base
end

a1 = Accessory.create

Widget.create(:accessory_id => a1.id)

pp Widget.columns.map(&:name)

puts Widget.exists?(:accessory_id => a1)  # should print "true"

output

/Users/davidyip/.rvm/gems/ruby-1.8.7-p302/gems/activerecord-3.0.0/lib/active_record/association_preload.rb:324:in `send': missing attribute: accessory_id (ActiveModel::MissingAttributeError)
	from /Users/davidyip/.rvm/gems/ruby-1.8.7-p302/gems/activerecord-3.0.0/lib/active_record/association_preload.rb:324:in `preload_belongs_to_association'
	from /Users/davidyip/.rvm/gems/ruby-1.8.7-p302/gems/activerecord-3.0.0/lib/active_record/association_preload.rb:323:in `each'
	from /Users/davidyip/.rvm/gems/ruby-1.8.7-p302/gems/activerecord-3.0.0/lib/active_record/association_preload.rb:323:in `preload_belongs_to_association'
	from /Users/davidyip/.rvm/gems/ruby-1.8.7-p302/gems/activerecord-3.0.0/lib/active_record/association_preload.rb:121:in `send'
	from /Users/davidyip/.rvm/gems/ruby-1.8.7-p302/gems/activerecord-3.0.0/lib/active_record/association_preload.rb:121:in `preload_one_association'
	from /Users/davidyip/.rvm/gems/ruby-1.8.7-p302/gems/activesupport-3.0.0/lib/active_support/ordered_hash.rb:126:in `each'
	from /Users/davidyip/.rvm/gems/ruby-1.8.7-p302/gems/activesupport-3.0.0/lib/active_support/ordered_hash.rb:126:in `each'
	from /Users/davidyip/.rvm/gems/ruby-1.8.7-p302/gems/activerecord-3.0.0/lib/active_record/association_preload.rb:115:in `preload_one_association'
	from /Users/davidyip/.rvm/gems/ruby-1.8.7-p302/gems/activerecord-3.0.0/lib/active_record/association_preload.rb:92:in `preload_associations'
	from /Users/davidyip/.rvm/gems/ruby-1.8.7-p302/gems/activerecord-3.0.0/lib/active_record/relation.rb:68:in `send'
	from /Users/davidyip/.rvm/gems/ruby-1.8.7-p302/gems/activerecord-3.0.0/lib/active_record/relation.rb:68:in `to_a'
	from /Users/davidyip/.rvm/gems/ruby-1.8.7-p302/gems/activerecord-3.0.0/lib/active_record/relation.rb:68:in `each'
	from /Users/davidyip/.rvm/gems/ruby-1.8.7-p302/gems/activerecord-3.0.0/lib/active_record/relation.rb:68:in `to_a'
	from /Users/davidyip/.rvm/gems/ruby-1.8.7-p302/gems/activerecord-3.0.0/lib/active_record/relation/finder_methods.rb:333:in `find_first'
	from /Users/davidyip/.rvm/gems/ruby-1.8.7-p302/gems/activerecord-3.0.0/lib/active_record/relation/finder_methods.rb:122:in `first'
	from /Users/davidyip/.rvm/gems/ruby-1.8.7-p302/gems/activerecord-3.0.0/lib/active_record/relation/finder_methods.rb:180:in `exists?'
	from /Users/davidyip/.rvm/gems/ruby-1.8.7-p302/gems/activerecord-3.0.0/lib/active_record/relation/finder_methods.rb:176:in `exists?'
	from /Users/davidyip/.rvm/gems/ruby-1.8.7-p302/gems/activerecord-3.0.0/lib/active_record/base.rb:439:in `__send__'
	from /Users/davidyip/.rvm/gems/ruby-1.8.7-p302/gems/activerecord-3.0.0/lib/active_record/base.rb:439:in `exists?'
	from exists_with_scope.rb:32