php variable de session guarda una clase, despues como logro guardar datos.

[lushiru]

la clase controlador si tiene la funcion :
class controladorventas_temp{
private $vventas_temp;

public function controladorventas_temp(){
$this->vventas_temp=array();
}
public function setventas_temp($newrec){
array_push($this->vventas_temp,$newrec);
}}

y el error q me da es:
Fatal error: main(): The script tried to execute a method or access a property of an incomplete object. Please ensure that the class definition "controladorventas_temp" of the object you are trying to operate on was loaded _before_ unserialize() gets called or provide a __autoload() function to load the class definition in /home/u369062475/public_html/lucho/presentacion/aj_venta.php on line 61

line 61:$_SESSION['venta']->setventas_temp($ven);