10g ORA-30625: method dispatch on NULL SELF argument is disallowed

I found this site for using a web service from oracle 9i. I'm trying it from 10g

http://www.oracle-base.com/articles/9i/ConsumingWebServices9i.php

I have an intranet web service I know is working as I use it from other clients.

but am getting this error when trying the example:

Getting error: ORA-30625: method dispatch on NULL SELF argument is disallowed.

on this line:

l_fullname := soap_api.get_return_value(p_response => l_response,

                                       p_name      => 'yyyResult',
                                       p_namespace =>

which calls this in the soap_api package i downloaded and installed from the stie:

FUNCTION get_return_value(p_response   IN OUT NOCOPY  t_response,
                          p_name       IN             VARCHAR2,
                          p_namespace  IN             VARCHAR2)

--
---------------------------------------------------------------------
BEGIN
  RETURN p_response.doc.extract('//'||p_name||'/
child::text()',p_namespace).getstringval();
END;
--
--------------------------------------------------------------------


My test script:



declare
  l_request   soap_api.t_request;
  l_response  soap_api.t_response;
  l_fullname  varchar2(50);
BEGIN

  l_request := soap_api.new_request(p_method    => 'ns1:yyy',
                                    p_namespace =>


'xmlns:ns1="urn:http://www.xxx.net"');


  soap_api.add_parameter(p_request => l_request,
                         p_name    => 'userName',
                         p_type    => 'xsd:string',
                         p_value   => 'somestring');

  l_response := soap_api.invoke(p_request => l_request,
                                p_url     => 'http://64.186.30.53/
securityservice/service.asmx',
                                p_action  => 'http://www.xxx.net/
yyy');

-- failing on the below  line(21)

  l_fullname := soap_api.get_return_value(p_response  => l_response,
                                       p_name      => 'yyyResult',
                                       p_namespace =>


'xmlns:ns1="urn:http://www.xxx.net/"');



 dbms_output.put_line(l_fullname);

  end;

Thanks for any help or information!!