Description:
------------
A ArrayObject containing a second ArrayObject cannot be unserialized.
The serialization differs from php5.2 to php5.3:
php5.3
C:11:"ArrayObject":180:{
	x:i:0;C:11:"ArrayObject":140:{
		x:i:0;a:5:{
			s:4:"date";i:1222539347;
			s:7:"session";s:13:"geF9ndWVzdF8w";
			s:5:"style";i:1;
			s:7:"friends";i:0;
			s:12:"friends_list";a:0:{}
		};
		m:a:0:{}
	};
	m:a:0:{}}

php5.2
O:11:"ArrayObject":5:{
	s:4:"date";i:1222539347;
	s:7:"session";s:13:"geF9ndWVzdF8w";
	s:5:"style";i:1;
	s:7:"friends";
	i:0;s:12:"friends_list";a:0:{}
}


Reproduce code:
---------------
$useronline = new ArrayObject(
        new ArrayObject(
        array('date'=>1222539347,
                'session'=>'geF9ndWVzdF8w',
                'style'=>1,
                'friends'=>0,
                'friends_list'=>array()
                )
        )
        );

print_r($useronline);echo "\n";

$r = serialize($useronline);
echo $r."\n";

print_r(unserialize($r));

Expected result:
----------------
should work like in php 5.2

Actual result:
--------------
Fatal error: Uncaught exception 'UnexpectedValueException' with message 'Error at offset 6 of 180 bytes' in test.php:18
Stack trace:
#0 [internal function]: ArrayObject->unserialize('x:i:0;C:11:"Arr...')
#1 test.php(18): unserialize('C:11:"ArrayObje...')
#2 {main}
  thrown in test.php on line 18