I just found out that the working webservice uses an utf-8 declaration in both the http header and the xml declaration.
Content-Type: text/xml; charset=utf-8
<?xml version=’1.0′ encoding=’UTF-8′?>
The webservice where the encoding isn’t correct, doesn’t have these utf-8 declarations. It even doesn’t have an xml declaration, after the http header the soap evelope begins.
Content-Type: text/xml
Transfer-Encoding: chunked
3d1
<soap-env:Envelope xmlns:soap-env=”http://schemas.xmlsoap.org/soap/envelope/“