I banned a user, didn't work, then banned unregistered

[cmp11]

The abuser registered, now how do I get his IP address to ban his access?

[Hugo <Nabble>]

You can go to your forum and click on "Options > Users > Remove user".
Enter the user name and click on "Check User" (make sure you found the abuser).
Check the "Ban this user" checkbox then click on "Remove This User".

Regards,
Hugo Teixeira
Nabble.com