Rafael, lscardin,
I think you're talking about two different things. I'm currently evaluating JForum (amongst others) for use on our company's web site, and as I was playing around with it, I stumbled across the same thing.
LOCKING/UNLOCKING works fine, as Rafael described.
UNBANNING doesn't seem to work as I'd expect, though.
Steps to recreate:
1. Log in as admin, find user ID of the user you want to ban.
2. Admin panel -> Banning -> add "Ban by User ID" with that user ID.
3. Open new browser, try to log in as the user you just banned. Message shows saying "You're banned". Fine.
4. Log back in as admin, go to Adminpanel -> Banning -> remove the ban you added.
5. Open new browser window, try to log in as "unbanned" user. You're still banned.
This is the case even after deleting all session cookies and the session data in the cache of JForum.
Restart JForum - user can log in again.
As lscardin said, we might be missing something here, or it might be an issue - you decide...
Cheers,
f.
[originally posted on jforum.net by fsattler]