Unless i am missing something, i really wish i do, Google Webmaster Central error message doesn’t make any sense at all. Google Webmaster Central > Site Configuration > Settings > Preferred domain. Google is asking me to first verify the owner of the domain. I did. Then Google is asking me to verify the owner of the domain again. I did. Google lets me know that the domain is verified using two different methods but it wants me to verify the owner of the domain again and again. It just doesn’t work. Bug or what?