PHP5 + Adwords API: scheduleReportJob = no go!

I tried to simply schedule a report job from ext/soap with the code below.... All it would do is tell me that I'm "missing default constructor." Here lies the rub - I have to specify the job's xsi:type to "KeywordReportJob" - but where do I do that in PHP5 ext/soap? (answer does NOT lie in documentation).. Also, if I were to manually do a __doRequest, I realized that the xmlns:xsi namespace isn't set in the SOAP envelope! Any help? <?php $ns = 'https://adwords.google.com/api/adwords/v2'; $headers[] = new SoapHeader($ns, 'email', 'x'); $headers[] = new SoapHeader($ns, 'clientEmail', 'x'); $headers[] = new SoapHeader($ns, 'password', 'x'); $headers[] = new SoapHeader($ns, 'useragent', 'x'); $headers[] = new SoapHeader($ns, 'token', 'x'); $client = new SoapClient(" https://adwords.google.com/api/adwords/v2/ReportService?wsdl", array("trace" => 1)); $client->__setSoapHeaders($headers); $client->scheduleReportJob(array("job" => array( 'startDate' => '2005-04-01', 'endDate' => '2005-04-01' ))); ?>