I am trying to sign up too and it isn't taking my social/first 4 letters of last name. i got my letter from ADA a couple weeks ago so i dont see why it isn't working, any ideas?
When you register the ADA sends you an email with all the info you need. Once you sign up you get a conformation number also with all your info. If you don't have those emails you can probably contact them and they will give it to you.