I've got a weird situation that I hope someone else has seen. We're in the process of migrating from Exchange 2003 to 2007, and the users rely heavily on OWA. So, I've installed a CAS role on a 2008 member server to act as the OWA server during the migration. The problem I'm having is this: The old implementation of OWA pulls the user credentials from the workstation login (Windows Integrated). I can get the CAS to work properly if I use Forms-Based Authentication, but if I try to setup CAS to use intergrated authentication, the only place it works is on the console of the CAS. From the workstations, the page requests credentials and eventually generates a 401 error of invalid credentials. Along with that, I get intermittent EXPROX errors. I've added the site to the local intranet, so the settings are not restrictive. Has anyone seen this before? Thanks, Chris Donaldson