We maintain a popular internet discussion forum on Apache server, using PHP scripts and MySQL database.
We have had a very strange problem for several months.
Nearly every day some users send feedback to the administration, and complain that they cannot log into the service: immediately at login they get the error message "Session expired" (which the system gives when the session actually IS expired). But how can the session be expired for some users immediately at login - still days after the person has last visited the service? Closing the browser doesn't help.
The problem is strange, because administrators have never been able to produce the kind of session error that tens of users complain of every week. When a user complains that he cannot log in to his account, administrators can log in with the same username and password without problems.
Somehow we administrators feel that maybe we have too fast and reliable Internet connections, too new browser models, and too new Windows versions. Maybe the reason why we never get the errors that ordinary users do, is that their Internet connections, browser models, or Windows versions are old or otherwise faulty.
Any opinions, ideas, advice: how can we help the users out of this mysterious problem?
