Hey, I bought my iPhone in September 2010, back then I noticed when I pressed the backplate, something clicks, like theres space between the backplate and the inside hardware. A few days ago, a friend of mine bought an iPhone 4 too, and I noticed that his is solid, nothing clicks or moves. It's not much of a problem, but that click drives me crazy. Is it normal? Could I swap my iPhone for a new one? Thanks a lot!