In Phorum 3, the data for the new message indicators was stored inside cookies. That way, both registered and unregistered users could see them. However, because of many cookie problems that plagued Phorum 3, we decided to store all user settings in the database for Phorum 5 instead. The down side of this is that users must be registered to show new messages. The up side is that the new indicators really work like they should in Phorum 5: messages that are read stay read when switching browser or computer.