En PHP: estoy recibiendo un error:

SOAP-ERROR: Parsing WSDL: Couldn't load from 'http://xxx.xxxx.asmx?WSDL' : 
failed to load external entity "http://xxx.xxxx.asmx?WSDL"

Mi código es:

<?php
header('Content-Type: text/plain');
    if (!class_exists('SoapClient'))
{

        die ("You haven't installed the PHP-Soap module.");

}

ini_set('max_execution_time',1 ); 
        try {
            $options = array(
                'soap_version'=>SOAP_1_2,
                'exceptions'=>true,
                'trace'=>1,
                'cache_wsdl'=>WSDL_CACHE_NONE
            );
            $client = new SoapClient('http://xxx.xxxx.asmx?WSDL', $options);
// Note where 'CreateIncident' and 'request' tags are in the XML
            $results = $client->CreateIncident(
                    array(
                        'FirstName'=>'gyaan',
                        'LastName'=>'p',
                        'Email'=>'[email protected]',
                        'QueryProductClass'=>'QueryProductClass',
                        'ChannelCode'=>12,
                        'CampaignCode'=>234,
                        'Lob'=>'Lob',
                        'PackageName'=>'SEONI',
                        'PackageCode'=>'SMP',
                        'TravelYear'=>2012,
                        'TravelMonth'=>06,
                        'TravelDay'=>29,
                        'CityOfResidence'=>'Jabalpur',
                        'ncidentNotes'=>'testing ignor this',
                        'MobilePhone'=>'1234567890',
                        'DepartureCity'=>'bangalore',
                        'NoOfDaysTravel'=>'3 Days',
                        'VendorName'=>'TEST HIQ'
                       )
                    );
        } catch (Exception $e) {
            echo "<h2>Exception Error!</h2>"; 
            echo $e->getMessage();
        }


?>

Por favor, dime dónde estoy cometiendo un error, soy nuevo en WSDL y jabón