Hi,
It sounds like you need to log out, and then log back in again using the login fields in the upper right corner. The center field only work once, at activation, and thereafter they don't function. We recommend that you try to log out and in again.
The other thing that may be happening is that your browser might still be using cookies from before the domain name change. You can clear your cache and cookies, and that way, the new domain will set the updated cookies. For your reference, the new domain is www.adult-fanfiction.org.
I hope this helps!