Creating default object from empty value

[jomeldicen]

I got problem when I started to upgrade my php version to 5.3.2 up but when I using 5.3.1 it works fine!

A PHP Error was encountered Severity: Warning Message: Creating default object from empty value Filename: controllers/crew_controller.php Line Number: ABC

Here is my API

 class Crew_controller extends MY_rest_controller
 {
  /**
  * Returns a single Crew.
  * 
  * @return xml
  */
 function crew_get()
 {
      $load = 'crew_id';
      if ($this->get('id') != '') {
         $id   = $this->get('id');     
      elseif ($this->get('hash') != '') {
        $id   = $this->get('hash');
        $load = 'hash';
     } 

    $cache = Cache::get_instance();
    $crew = $cache::get('crew' . $id);

    if (!$crew) {            
        $crew = new Crew($id);   
        $crew->load($id, $load);  
        $cache::save('crew' . $crew->crew_id, $crew, 1800);
    }

    $response = $crew->getData();   

    $this->response($response);
   }
}

And here is my FRONT Controller

    class Crew_controller extends Front_Controller
    {
      public function crew_registration($crew = null)
  {
       $personal = $this->rest->get('crew', array('hash' => $crew), 'json');    
       $personal->first_name            = $profile->first_name;   ->>>>> LINE ABC
       $personal->last_name             = $profile->last_name;
       $personal->thumbnail_url         = $profile->thumbnail_url;
      }
    }