I am taking my iPhone 5 in to the AppleStore today because the power button is not working. I have my device synced to my computer and my phone has done a full back up to iCloud so I am not worried about the data. I remember reading some time ago that some people were having iMessage issues with replacement phones where the old device would still be registered in the iMessage system and the new one is unable to sync with iMessage. Has anyone done this or have any insight into how to prep my dying phone for this process? Thanks!