Registration problem

I'm having an issue with someone trying to register on my forums. They try to register and get a message that reads

"Sorry, but that e-mail address is already registered to a user.
Sorry, but this username has already been taken."

I went through all my members and I know neither their e mail or name was taken how do I fix this

Try checking a new e-mail & username, just in case.

Also make sure that he hasn't already registered without knowing (Admin Panel -> Users & Groups -> Inactive users).

Thank You! Thats where they are, they must have signed up and either forgot about it or the confermation e mail was sent to the spam folder or something...