I don't know about this but when I'm at school, phpbb based forums are automatically logged out a second after I log in. I have created the
Programmers' forum. When I'm at home, there's no problem at all. I was given the impression that phpbb doesn't allow users to access the forum with a single public ip address. However, I asked some of my colleagues in a software development company to try to simultaneously access the forum, but they found no problem. Could it be the firewall? Our university is using Juniper for firewall. I tried another phpbb based forum and the problem is still the same.