Not sure if this is just my i4 but I have no one around me that has a i4 test this on. I noticed the other day when I put my i4 down it slipped from my fingers on about 1/2" and heard a rattle like sound coming from the back upper part of the i4 when it landing on my carpet. So picked up the i4 and tapped it where the Apple logo is and still could hear the rattle sound. I wanted to know if others are hearing the same thing before I take it to Apple. If it is just my i4 I will take it apart to see what came lose or what is rattling. I like my i4 and don't want to take the chance of getting something less. Please let me know.