Hi, we've experienced a very strange and critical behaviour with one of our users. He reported us that he was working normally with his user, and after a break, first time he clicked somewhere suddenly the system had changed to another user and displayed the homepage. Then he had to logout from that user, and log in again with his own user, to continue working.
Of course this is a very critical and dangerous situation, because our site is an intranet, and some users can't update data that other users can't.
We've seen that there're some users who have the init field empty, in the users table, probably because of an old migration, but that doesn't seem to be the problem.
Also we've seen some code in drupal, where the variable $user is used locally, or even sometimes replaced by user_load(1), followed by a call to drupal_save_session(FALSE).
Does anybody know if that can be the cause of our problem? Or has anybody heard about some similar problem before?
Thank you very much in advance