This post gives half the answer I needed to test SOAP services . The other half of the answer was to override the default Content-Type HTTP header added by pingdom (Check the 11th point in the Optional Parameters section).
To override the header, just add one with a blank space. This worked for me and may be for you too.
Also another thing I had to do while testing web services developed using Apache Axis (I don't know which version), is that I had to specify a SOAPAction header with the value "" (The value is 2 double quotes, not an empty value)
Generally, you need successfully send a POST request to the service and find out what HEADER you are missing (i.e. to add it) or adding (i.e. to remove it). You can use SOAP UI to do that. But SOAP UI doesn't show sent HEADER by default, so you'll need to download TCPMon (Which records and displays communications), start it, and let it proxy connections on a specific port, then configure SOAP UI to use that port as a pro…