Hey guys, I just upgraded to an AT&T iPhone 4S from a T-Mobile unlocked + jailbroken iPhone 1, but I want to get my stuff off of my old phone. The girl at the AT&T store said I can back up on iTunes and it's no problem, but I'm scared it's going to do something bad to my phone. I plug in my iPhone 1 and I can hit the "Sync" button, but do I dare? What will happen? I need guidance!