I must say that I do like the fact that logins expire, however, sometimes it is a little difficult to navigate when the session has expired.
For instance, I have a subsite which requires a membership. Navigating that subsite allows me to do everything, however, I am the administrator of the FAQ module, and no Administrator link exists. So, I must log in. Currently, I hit Admin or Your Account, log in, hit back, reload, and then my Administer link shows up.
Except for the fact that I don't see the Administer link, I wouldn't know that I wasn't logged in. Perhaps there is a way for OpenACS to recognize that hey, this user does have admin, but, as soon as an admin link is clicked, it prompts for login. I know there are packages that do this when the admin link is visible, i.e. ad_maybe_redirect_for_registration/ad_redirect_for_registration.
Perhaps that might be a little less confusing.
Maybe the 'Welcome, User Name" could become a link to re-login if the person was not logged in. That would at least signify that there was another status.
I hate to add yet another button, things in the title bar seem crammed in enough as it is. Perhaps the Logout Button could be changed to Login/Logout.
Just some thoughts.