The webservice is returning a float value to the client via the proxy, the method is marked as a SoapRpc method. Essentially the IBM redbook 'WebSphere MQ Version 6 and Web Services' says the once you ...
Windows XP Professional 2002 Service Pack 2
MQ V6 with Maintenance pack 2.1
Microsoft .NET runtime 3.5
MQ Queue manager installed locally, called 'QM_LOCAL'