I have been using Google Analytics happily for some years. Suddenly - wake up Google! - the only place that I am guided to when I try to login is a page that assumes that I have no account at all and the I should "sign up".
We are not all first time users you know. Worse, there is no link to a login page anywhere. Just look more carefully at what you are doing and stop making silly assumptions. Its as bad as people / designers that think because you live in a particular country you will be able / wish to communicate in that country´s language. Another basic assumption mistake!
Simple things like the above can turn users off your services for ever!