Problems with identity map on self-referencing

/**
 * @Orm\Entity
 * @Orm\Table(name="tt_content")
 */
class Page
{
	/**
	 * @Orm\Id
	 * @Orm\GeneratedValue
	 * @Orm\Column(type="integer", name="id")
	 */
	protected $id;

	/**
	 * @Orm\ManyToOne(targetEntity="Page", inversedBy="children")
	 * @Orm\JoinColumn(name="pid", referencedColumnName="id")
	 */
	protected $parent;

	/** @Orm\OneToMany(targetEntity="Page", mappedBy="parent") */
	protected $children;

	/** @Orm\Column(name="page_title") */
	protected $title;
}

$id = 5;

// step 1 
$page = $this
	->getEntityManager('read')
	->createQuery('
		SELECT p, parent
		FROM OloloContentBundle:Page p
			LEFT JOIN p.parent parent
		WHERE p.id = :id
	')
	->setParameter('id', $id)
	->getOneOrNullResult();

// step 2
$page = $this->getEntityManager('read')->find('OloloContentBundle:Page', $id);
var_dump($page->getParent()->getParent()); // expected instance of Page, but got null