The "problem" appears to be the automatic logout based on a timeout that is built into the web site. So even though your login has timed out you can still see your top level information but things like "Viewing all Activity" require you to re-enter your password. Same with the expert mode, it will let you look for flight, but if your login has timed out it doesn't know that your profile has that set. Solution is to always force a login (or go to a page that requires a login) prior to searching for a flight.