Here are links to a couple of threads about similar problems:
https://www.mobileread.com/forums/sho...light=creaking
https://www.mobileread.com/forums/sho...light=creaking
I don't have my Kindle yet (just ordered it) so I can't personally address your problem, but I would say if you have any concerns about your Kindle falling apart you should email/call customer service to request replacement. From what I have read here, Amazon will send you a new unit and you don't have to return the old one until you receive the new one.
Holly