I'm having some problems when from a Soap Sender destination I call a webservice that is developed with MSSOAP toolkit.

I'm getting the error:
"SoapMapper:Restoring data into SoapMapper string failed"

The method I'm invoking needs only a parameter, that is an XML as string. The XML is prepared in a few transformers and is 100% correct.

I've found some posts like this one
from people stuck with the same problem, but in Mirth I don't know how to modify the stub (if needed).

Have someone faced this problem or succesfully invoked MS-SOAP services from Mirth?

Any suggestions will be appreciated.