I have a MS account. I know the password. I am logged currently in at https://account.live.com/proofs/Manage

Today my brain left me for a moment and I bought a Windows 8.1 phone (640XL).

No matter what I do I cannot long in with my Microsoft online account. The phone says the password is wrong, which it isn't.

I tried creating a new account and again, on every login attempt I get the wrong password error.

Does anyone know what kind of new Microsoft madness this is and how I might avoid it, short of donating the phone to the local Op Shop?