mypaga on "Mapped Domain but getting an advertising page!"

I mapped my domain www.pagablog.com to my wordpress domain mypaga.wordpress.com. I changed my DNS on goDaddy. When I go to the URL I get an advertising holding page. Similar to what you get when you just signed up for a URL. I did a trace route and the URL is definitely pointing to wordpress.com.

Any ideas? Would appreciate any help

Thanks