I see that I have called the wrong file.
It is not the COD, but it is the moneyorder.php.
My mistake, but when I use the following code:

Code:
if (!strstr($_SESSION['customers_id'],'3739')){
      $this->enabled = ((MODULE_PAYMENT_MONEYORDER_STATUS == 'False') ? true : false);
      }
With the ! than the option is not showing at all