FaceTime keeps rejecting my sign-in...

i hardly ever use FaceTime, but, i had noticed the FaceTime icon showed a "3" with it on the dock. so, clicked on FaceTime and went to sign in with my email and Apple ID. i keep getting an "error" message, so, i try again and it still keeps showing or telling me to try again. i went over to iTunes and tried my Apple ID there and it accepted it, so, it must not be my Apple ID. the only thing that confused me a bit was, the sign-in box shows Apple ID on top yet the example it shows is an email address and then below that it asks for the password. i tried inverting the sign-in and either way it still tells me an error occurred and try again.