imessage & facetime sign-in (solution)
Yesterday I ran into this and thought I would post the "solution" for the issue.
Problem: I verified I could log into the Apple community using the username and password I had set for my Apple ID, works fine. When I try and click on FaceTime the login failed repeatedly no matter what we tried.
Solution: Use your @me.com email address (Apple automatically created you can see this on your profile screen) vs. your email address and your password to log into FaceTime. (This will work). Once you are logged into FaceTime click the "View Account" button in FaceTime and this time use your email address you would normally use. This will authenticate you and you can view your account in FaceTime. Once you have done this log out of FaceTime and "magic" now you can use your normal email address & password for FaceTime and it will work.