Description:
------------
i the case of class "B" extends a class "A" wich define the function __sleep(), instances of class "B" would class A::__sleep. In this case class serialzing would be very buggy - i tried something like:
Try: let return the __sleep of class "A" all propertys wich are currently definied
resoulting Problem: private properety of class "B" are null or NAN
Try: define the function __sleep() in class "B" 
resoulting Problem: private properety of class "A" are null or NAN


Test script:
---------------
class A{
	public $A_A = 10;
	protected $A_B = 11;
	private $A_C = 12;
	public function A(){
		
	}
	private function __sleep(){
		echo "sleep of A()";
		if(get_class($this)	!= "A")
		{
			$d = array_keys( get_class_vars(get_class($this)));
			return ($d);
		}
		return array("A_A","A_B","A_C");
	}
	public function __get($v){
		
		return "PR";
	}
}
class B extends A{
	public 		$B_A = 20;
	protected 	$B_B = 21;
	private 	$B_C = 22;
	public function B(){
		$this->A();
	}
	public function __sleep(){ 
		return array("A_A","A_B","A_C","B_A","B_B","B_C");
	} /* remove this __sleep would let php use A::__sleep()

}
$a = new A();
$b = new B();
echo "<br/>A";
echo "<br/>" .  htmlspecialchars(serialize($a));
echo "<br/>B";
echo "<br/>" .  htmlspecialchars(serialize($b));


Expected result:
----------------
the complettely serialized Object like with out __sleep()!

Actual result:
--------------
private propertys of parent or child are null or NAN with defined __sleep()