Chat

I have a moodle, with a chat in normal mode.

When I login to the chat room the chat's window appear but only show me the message of "No loggin!!!" and don't let me send messages.

I have a configuration of 3 web servers but only 1 DB (Postgresql) and the File System for php sessions is the same, shared by NFS, then It isn't problem of sessions or DB.

What happen!, is a problem of ports? we have a Firewall... or what's the problem! please help me, cause the children begin to hate me :'-(