I had problems working with and Internet based SharePoint server with Internet based clients. I was talking to Mark Minasi about this (Kerberos talk) and a kind stranger came in with a fix.
- Patch for SharePoint (KB number unknown at the moment – released this past Summer).
- Enable forms based authentication for the application.
- Enable delegation for the SharePoint server. Need to create 2 SPN’s: one for machine name and a domain based server account with no user rights.
Thanks to Graeme Hill (CT, Chalmers University of Technology).