soap4r error: undefined method `find_message' for nil:NilClass

[Giacecco]

Very little code, very big error

---
require 'soap/wsdlDriver'
WSDL_URL = 'http://RLS-4-011:9700/orabpel/default/SendSms/SendSms?wsdl'
factory = SOAP::WSDLDriverFactory.new(WSDL_URL)
driver = factory.create_rpc_driver
---

You find a copy of the wsdl at http://www.giacec.co.uk/ruby.wsdl
(RLS-4-011 is a private server).

The error I get is:

ignored element:
{http://schemas.xmlsoap.org/ws/2003/05/partner-link/}partnerLinkType
C:/ruby/lib/ruby/1.8/wsdl/operation.rb:67:in `outputparts': undefined
method `find_message' for nil:NilClass (NoMethodError)
from C:/ruby/lib/ruby/1.8/wsdl/soap/methodDefCreator.rb:72:in
`collect_documentparameter'
from C:/ruby/lib/ruby/1.8/soap/wsdlDriver.rb:132:in `create_param_def'
from C:/ruby/lib/ruby/1.8/soap/wsdlDriver.rb:101:in `add_operation'
from C:/ruby/lib/ruby/1.8/soap/wsdlDriver.rb:96:in `each'
from C:/ruby/lib/ruby/1.8/xsd/namedelements.rb:57:in `each'
from C:/ruby/lib/ruby/1.8/xsd/namedelements.rb:57:in `each'
from C:/ruby/lib/ruby/1.8/soap/wsdlDriver.rb:96:in `add_operation'
from C:/ruby/lib/ruby/1.8/soap/wsdlDriver.rb:40:in `create_rpc_driver'
from C:/dev/Eclipse_Ruby_workspace/SMSGatewayTest/SMSGatewayTest.rb:7

The first line seems trivial, even if it seems a soap4r problem anyway.
I can read the definition for "partnerLinkType" at
http://schemas.xmlsoap.org/ws/2003/05/partner-link .

The second is serious, and I have no idea of what to do. The web
service and wsdl are realised using Oracle BPEL Process Manager.

Thank you in advance for any help,

Gianfranco