From your stacktrace I see:
com.sun.xml.ws.client.ClientTransportException: HTTP transport error:
java.net.ConnectException: Connection refused at
Are you sure you have the correct hostname & port? Maybe you need some firewall access rules on the server side? What happens if you curl the url, or open it in your browser?
Btw, the cloud security concerning ports shouldn't be an issue: we've opened SocketPermissions completely.
Olaf,
Just the first thing that springs to mind is that the cloud environment does not allow the socket connect to a specific port. Maybe something to do with the cloud security settings.