If the squeaky screen is the only problem you're having, and I guess it is just hard to duplicate, then just let it go. If your phone ever has other issuess (broken home button, battery sucks, etc.) then go and try and get it replaced/fixed. If they are still giving you issues LET ME KNOW! They HAVE to repair it. The only reason it seems that they are not doing it now is because of they can't find the problem you're describing and are just assuming its the sides that you have a problem with. If you have an easy to replicate problem and they don't replace due to the sides being like that, then they have problems. If they classify that as being a cosmetic defect or a modification then all of their black iPhones will have voided warranties. Just like what I told you earlier where Apple said themselves that it will eventually strip and reveal the silver. I promise you that I will ensure your iPhone is fixed or replaced if your problem is really that bad and easily replicated or if you have another one. No matter what I have to do.