Change Content-Type in webservice call

Hello!

I call a Java-based web service from HC and get an error message back:

"ERROR # 6243: HTTP request to SOAP WebService returned response with unexpected CONTENT-TYPE: text / html; charset = utf-8."

The content (payload) that is sent from my HC-client is coded in iso-8859-1 but SOAP debug shows that Soap envelope  to be sent with:

"Output from Web client with SOAP action = urn: submitFile
<? xml version = "1.0" encoding = "UTF-8"?> etc "

and I guess that's what is causing the error message?

How can I change from "UTF-8 to ISO-8859-1 in the soapcall??

Grateful for answers!

Regards Michael