Hm, not sure what to tell you. Check the country you have specified in your account settings too, it has to match. All I can say is that I was able to create a "US Google Account" where my country said "United States of America", but was denied when I tried to access Google Voice. My Tor endpoint was in Russia. When I directed Firefox to use an HTTP proxy with a US endpoint, Google Voice fired right up and let me choose a phone number. Hope that info helps somehow.