Doctrine_Record::free(true) を実行すると同一レコードを指す別のインスタンスまで解放されてしまう

gistfile1.php

<?php
include_once dirname(__FILE__) . '/../../bootstrap/unit.php';
include_once dirname(__FILE__) . '/../../bootstrap/database.php';

$t = new lime_test(3, new lime_output_color());

$community1 = Doctrine_Core::getTable('Community')->find(1);

$t->is($community1->id, '1');

$communityMember1 = Doctrine_Core::getTable('CommunityMember')
  ->findOneByCommunityIdAndMemberId(1, 1); 

$t->is($communityMember1->Community->id, '1');

$community1->free(true);
// $communityMember1 や $communityMember1->Community に対しては free() を呼び出していないはず

$t->is($communityMember1->Community->id, '1'); // エラー

/*

  Doctrine_Record_UnknownPropertyException: Unknown record property
  / related component "id" on "Community"
  (in
  lib/vendor/symfony/lib/plugins/sfDoctrinePlugin/lib/vendor/doctrine/Doctrine/Record/Filter/Standard.php
  on line 55)


Exception trace:
  at lib/vendor/symfony/lib/plugins/sfDoctrinePlugin/lib/vendor/doctrine/Doctrine/Record/Filter/Standard.php:55
  Doctrine_Record_Filter_Standard->filterGet() at lib/vendor/symfony/lib/plugins/sfDoctrinePlugin/lib/vendor/doctrine/Doctrine/Record.php:1395
  Doctrine_Record->_get() at lib/util/opDoctrineRecord.class.php:180
  opDoctrineRecord->_get() at lib/vendor/symfony/lib/plugins/sfDoctrinePlugin/lib/vendor/doctrine/Doctrine/Record.php:1350
  Doctrine_Record->get() at lib/util/opDoctrineRecord.class.php:161
  opDoctrineRecord->get() at lib/vendor/symfony/lib/plugins/sfDoctrinePlugin/lib/vendor/doctrine/Doctrine/Access.php:72
  Doctrine_Access->__get() at test/unit/model/gistfile1.php:19
*/

関連: http://stackoverflow.com/questions/16353115/doctrine-1-x-unknown-record-property-bug-after-free