UBB.Developers Forums General Discussion Chit Chat How to determine ip address

I have 6.4 ubb.threads and have constant bogus registrations I think from the same person. They dont post to the forums and thats the only place I've ever seen an ip address associated with userid. Is there another way to determine the ip address so I can ban that rather than the email?

Thanks

BTW - I didn't have permissions to post to "How to" forum.