ich vermute, du musst den Endpoint setzen
DEIN_SOAPENDPOINT = http://search.webofknowledge.com/esti/wokmws/ws/WOKMWSAuthenticate
try{
$this->soapClient = new SoapClient(URL_ZUR_WSDL, array('trace' => 1, 'login' => "dein_loginname", 'password' => "dein_password"));
$this->soapClient->__setLocation(DEIN_SOAPENDPOINT);
}
catch(SoapFault $fault) {
echo 'faultstring: '.$fault->faultstring."\n";
print_r($fault);
}