If you need to register/unregister twice until the change is reflected - just delete cookies and files in Internet Explorer, tools->Internet Options.
There was a problem with DNS and I replaced netwu.com with its IP address, then I changed it back, it seems those who logged in at the time may have the problem.
It seems there is a bug in IE that causes that, if you delete cookies/files it disappears.
If you don't see this - no need to do anything.