"Namespace error" on import of WSDL using schema-includes

Dear reader,

When I use the WSClient to call a webservice defined in IBM Websphere ESB by a WSDL which uses several layers of imports, performing the actual call results in the following errormessage:

"Namespace Error"
/export/home/nhoozemans/projects/zigcm/wsoscripts/dynamic_invocation/wsf_wsdl_client.php
Line 104

In the lines:

$client = new WSClient( array("wsdl"=>"...") );
$proxy = $client->getProxy();
...
$output = $proxy->Operation(array($input));

The error only occurs at execution at the last line.

the peculiar thing is that when I gather all includes into one WSDL, the code works flawlessly.

This leads me to believe that there is something amiss with the WSO-objects ability to work with WSDLs using imports or includes.

Does anybody have any data on this?

Thanks in advance,

G.