Two account using the same username named Admin

[vip.vandan]

Hi all.

In my forum, I create an Admin account with username is admin and userid equal to 1. This account can control and manage all aspects of the forum.

Recently, my forum has been harmed by someone. I don't know how but he can create an account with the username admin. Although it has a different userid, and I don't activate the account yet, my forum still suffers a damage: everytime, I create a new thread or post using admin account, there is a duplicate created.

I wonder how this error some so I hope that any of you can help my on that.

Thank you very much.