<A target="_blank" href="http://blogs.perficient.com/portals/2011/05/03/user-impersonation-in-websphere-portal/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+PortalSolutionsBlog+%28Portal+Solutions+Blog%29">Michael Porter has posted a 9-minute video by Cody Burleson </A>explaining how you can use User Impersonation in WebSphere Portal for trouble shooting.