Description:
------------
get_object_vars crashed with object from COM-class

Reproduce code:
---------------
<?php

$outlook = new COM("Outlook.Application") or die("Kann Outlook nicht ?ffnen");
$namespace = $outlook->GetNameSpace("MAPI");
$contacts = $namespace->GetDefaultFolder(10);
$messages = $contacts->Items;
$length = $messages->count;

for ($i = 1; $i <= $length ; $i++)
{
  $item = $messages->Item($i);
  $arr = get_object_vars($item);
  print_r($arr);
  die();
}

?>

Expected result:
----------------
array (...)

Actual result:
--------------
crash