Hey
David35,
I might be misunderstanding your issue, but i'll try and help cos no one's responded to this as yet.
How you attach or embed a file within a SOAP request is surely defined by the functional requirements and so id expect the tags within your payload xml to lead you to determine the approach....in actual fact id expect the requirements to indicate if you attach the file MTOM, etc. or embed the file, whether you base64 encode the file, etc.
So! What do the requirements say?
Can you publish the payload xml?
Ta
Rich