My Kindle started rattling a few minutes ago. I tried to turn it on and saw something blocking the light on the switch, and then the rattle started. It does sound like either a small screw or a small piece of plastic.
I called CS and they are shipping me another Kindle that should arrive tomorrow. I wonder how much in shipping fees they are wasting due to this issue :/ Hopefully the new one won't have the same issue.
ETA: Mu Kindle just went kaput on me. Won't turn on or anything now. Good thing I called and requested a new one.