I am uploading a file using a simple FileUpload control named
Dim fStream As New FileStream(thefile.FileName, FileMode.Open, FileAccess.Read)
A file uploaded through HTTP will never contain the full path on the remote (client) machine - it could give away information about their directory structure, and so is considered a security risk. Plus, what use would it be? If someone is uploading you a file from over the internet, why would you be trying to open a filestream on your local (asp.net server) machine to the path that existed on their machine?
Uploaded files actually come through as a stream of bytes as part of the request. You need to access the FileBytes property of the control to get the file, or call the SaveAs() method to save it to the server. In your case, you could probably just get the bytes and send them off to the webservice call you need to make.