InfoPath Dev

I have a browser-based full-trust InfoPath form.  In the managed code I've added to web services (userprofileservices and lists) as web references.  I'm able to query the values for the userprofileservices, but the lists query returns a 5337 (double hop) error.

The problem is likely coming from the authentication method.  Our users don't use AD, but login through a Shibboleth system using 9Star ActiveShareFS.

The lists web service is accessible to any user of the site, and using an AJAX/SOAP in webpages to retrieve list data doesn't cause me any problems.  I'm thinking it has to do with the credentials I'm supplying for the list web service, which is the standard: UseDefaultCredentials = true;

Any thoughts would be appreciated.

 -Eric

Why do you need to write code to query UserProfileServices and Lists? Why not just add data connections and then convert them to UDC files. If you do that you could change the credentials of the UDC proxy to access SharePoint using specific credentials. Of course that wouldn't pass the user names through though. Have you looked at creating a Single Sign On mapping?