The lookupPartners() method has "http" hard coded for creating the URL to access the federated resource of partners. When the request comes from a secure connection the method throws a org.apache.commons.httpclient.ProtocolException (The server whatever failed to respond with a valid HTTP response) since it is trying to access a URL as such http://whatever:443/federate/partners. The header returns garbage since it is trying to access a https resource using http. The method needs to be changed to use request.getScheme() to build the URL instead of the hard coded "http" string.
Mahalo,
Dennis