Its because you (or another admin or the user themselves) has tried to change the email address associated with the member account. The user must never have clicked the link in the email they get to confirm the change.
What to do next will depend on what the user wants to do.
Can she not use the account she already has ? If she cannot access the forum using the old account you could change the password for her. Or are there two users who are claiming the same email address?
No, she can't log into the forum - when I put her details in the member list - it shows member not found - when I put her details in the e-mail list - it shows member not found - when I try to register her - it says e-mail is in use -
I've got another new member who is having the same exact problem -
Please check your private messages as I have sent you the first member's details so that you can see what it is doing -