nothing from SOAP over HTTPS.. out of clues

Hello, I'm trying to write a simple SOAP client. This client has to authenticate and must work in HTTPS mode. In the facts, everything's alright when working in HTTP mode (results, exceptions thrown if errors etc..), but I haven't managed to get a single output when switching to HTTPS mode: no exceptions, no warnings or notices.. PHPinfo has soap functions and https stream enabled. I can fopen a https doc. Searching google for the last 2 days didn't give me more clues Here's my code: try {

     $client = new SoapClient("my.wsdl", array(
       'login' =>"login",
       'password'=>"pass",
       'local_cert'=>"/path/to/my_cert",
       'trace'=>true,
       'soap_version'=>SOAP_1_1
     ));

} catch (SoapFault $fault) {

       DisplayError ($fault);

} try {

     $req_xml = make_xml_request ($some_data);
     $ret = $client->__doRequest ($req_xml, 'https://my.web.service',

'', SOAP_1_1); } catch (SoapFault $fault) {

       DisplayError ($fault);

} print_r ($ret); I've tested this with PHP5-cli on a ubuntu (php5.1.2) and debian sid (php5.1.6), with the same result. Strictly no output, no clues. Tcpdump gives me some HTTPs traffic, so there must be some dialog. Questions: - is this a known issue? has someone ever written such a piece of code? - how can I get more debugging info? Thanks in advance for any kind of help