Google Webmaster Central, verified but not preferred
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?
http://www.pestaola.gr and pestaola.gr is considered to be another site by Google, because www. is a subdomain.
That means that you have to validate both of them.
In theory, you could have another site in http://pestaola.gr with another administrator than in http://www.pestaola.gr.
Both sites are validated using 2 distinct methods. Current setting is www but when changing to non-www the error message appears even though (see screenshot) non-www is validated