Soap Fault

Hi,

I am trying to call a Web Service using Php and Soap.

Why does the following Php 5 code return?

try
{
//$ExchangeLoginResult = $ExchangeClient->Login(array("request" => array("username"=>"sportleisure",
$VendorAddResult = $VendorSoap->updateVendorSubscription(array("request" => array("header"=>$BetfairRequestHeader,"username"=> $tok
[3],"vendorSoftwareId"=>342,"expiryDate"=>$date))) ;
}
catch (SoapFault $fault)
{
trigger_error("SOAP Fault: (faultcode: {$fault->faultcode}, faultstring: {$fault->faultstring})");
print("Fault when trying to Add/Update API User ");
var_dump($fault);
}

Error Message - Fault when trying to Add/Update API User
["faultstring"]=> string(22) "Rejected (from client)"
["faultcode"]=> string(10) "env:Client"

Thanks,