Jforum, new member could not login again

[Migrated From Jforum.net]

Now, Our forum have 4000 members, old mems can login anytime, but new members just only one when they've register member of forum they can't login again.
[originally posted on jforum.net by romapt123]

[Migrated From Jforum.net]

Not much info to go on here...

Any error messages associated with this? Either what the new members see or in the log files? What version, what environment (OS, J2EE Container, Database, and the like)

Have you check the obvious stuff like hitting a DB allocation limit? (E.g., new info can't be saved).
[originally posted on jforum.net by monroe]