I can't find any other posts about this so will just ask...
We are using the QTP Web Servcies plug-in and finding it VERY buggy! Is anyone else using this and can you post your comments about it please? We are struggling to use the tool productively and can't believe Mercury have released such a bad product.
I'm not sure what HP's strategic decision was with this addin. They also have a dedicated tool call service test (https://h10078.www1.hp.com/cda/hpms/display/main/hpms_content.jsp?zn=bto&cp=1-11-127-24^1382_4000_100__)
I have to agree with 'stth10' there on the WS-Addin for QTP. I was able to successfully post some XML to the Webservice without using the WS Plugin and it seemed to work much better that the built-in functions of the WS Plcugin. The WinHttp calls seem to be a little more configurable than the 'easy' WS Plugin features.
I also downloaded the soapui.org tool and find it quite helpful. If nothing else, you could always just create a quick HTML post test page that would suck in XML and provide a response back.