Having a weird issue with GPO's on a thin client architecture running windows 2003 enterprise. Apply a GPO for IE to use local intranet vice internet and gpupdate on the application servers. The next day only some users are needing to re-authenticate. I could not replicate this in the lab at all, no matter what options I selected for authentication. The only odd thing is most of ther servers including the DC are on IE7 and the ap servers are running IE6. Any one experience anything like this before? or may know of possible causes? Thanks in advance for any help.