>David,
>
>But why would that nuke a Session variable? I guess I'm not 100% with the event model - are you saying that the Page.Redirect starts a new Session - it thinks you are coming into the web site for the first time? If so, how come this does not always happen?
>
>But hey - makes sense. Do you have an example of the login code for me to swipe or look at?

Start here. Their simple scenario isn't realistic but you can do a search for forms authentication. You should find many hits.
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cpconsimplecookieauthentication.asp

I don't know whats going on with the session variable. The Redirect will not wipe out session, but it will wipe out viewstate.