User (free membership level) registered but mistyped the username she wanted.
Since she (or I) cannot revise a username once set, I offered to delete the incorrect registration and re-register her with the correct username she wanted, same email address (she only has one), same password, same first name.
I am getting
Email:The email address you are using is already taken!
Please choose a different email address. .
This person/email address is not in the WP users (I am the only one), nor has she ever been (I had checked there before I deleted from eMember).
Where the heck is the system remembering this email address and what can do to get this to work?