When I click 'sign in" on iMessage (through settings and the app) the screen pans to the next screen then back to the apple id screen. I'm not getting any error messages and cannot get out of the activation screen (cannot turn iMessage on/offer change anything else). I do have an Apple ID and I've tried to reboot (it does work on my iPod Touch). It did work at one time but wasn't delivering my messages, so I tried signing out and back in and that's when I started having this issue.