okay, here's my situation. I tend to reformat my computer(s) quite often which means everytime I hook up my iPhone iTunes starts crying about how my iPhone is synced to a different computer. it then wants me to erase all my music and videos. how can I stop this? I see where it says that I can authorize up to five computers, but I don't exactly know what that means. it's telling me I have five computers authorize and that I'm at my limit. can someone who knows something about iTunes clue me in?