Hi Fink,
Thanks for signing up! I don't know what it would do that, but I would suggest first removing all your cookies or turning them on if they are off. Also, try resetting your password and see if that helps. Let me know if that doesn't do it.
No luck. I've tried resetting password and I've tried across four different browsers. In Safari the password input field would disappear after I had typed in my e-mail.