Add namespaces in SOAP-Envelope (serverresponse)

Hi,

is it possible to add additional namespaces in a soap-envelope?
Actualy I'm receiving the following answer from my soap-server:
<?xml version="1.0" encoding="utf-8"?>
<env:Envelope xmlns:env="http://www.w3.org/2003/05/soap-envelope"
  xmlns:ns1="http://www.example.de/example/ServiceCaseMessages.xsd">
  <env:Body>
    <ns1:CreateUpdateServiceCaseResponse>
      <createUpdateSuccessful>true</createUpdateSuccessful>
    </ns1:CreateUpdateServiceCaseResponse>
  </env:Body>
</env:Envelope>

But I was expecting:
<?xml version="1.0" encoding="utf-8"?>
<env:Envelope xmlns:env="http://www.w3.org/2003/05/soap-envelope"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns:xsd="http://www.w3.org/2001/XMLSchema"
  xmlns:ns1="http://www.example.de/example/ServiceCaseMessages.xsd">
  <env:Body>
    <ns1:CreateUpdateServiceCaseResponse>
      <createUpdateSuccessful>true</createUpdateSuccessful>
    </ns1:CreateUpdateServiceCaseResponse>
  </env:Body>
</env:Envelope>


Like you can see the namespaces xsi&xsd are missing in my response.
Would must/can I do to get a response like the expected?
I've been googling for a while and I saw a lot of examples where this to
namespaces where included, also in books. But no one writes how they've
done it. So there must be a way in the corntuctor, class-methodes or
-attribute or in the wsdl-file?

I'm using php 5.2.12 self-compiled by source on a Linuy System
(--enable-soap) and Apache/2.2.15 in case this information could be
helpfull.

Thanks a lot,

Karfunckel