This is pissing me off. I have a new 4S. I also have a new MBA. I did a backup/restore of my iPhone 4 to the 4S, but now anything I want to do through itunes gives me the "If you sync, any apps from this phone will be erased and replaced with the ones on this computer" or the same message, but with music. why is it so impossible to have your iphone work with more than 1 computer? How can I fix this?