I took a look - are you still having an issue with Validation? JBoss ESB ships its own validation action :
It seems to do something very similar to what you are doing - you might want to replace your custom Validator with it, or maybe by examining the code you can discover what's going wrong in your validator.
Have you taken a look at the webservice_proxy_basic quickstart?
Yes, The issue is that custom validator does not validate the request against the WSDL. When ever request starts with <SOAP:envelop> It always consider it as invalid request. Also, I cannot hanlle the exception thrown by inbuilt validator gracefully.
Please let me know the correct steps.