So I ordered my iPhone 3GS via FedEX through AT&T and however it has been only a week and just noticed that there is light leaking coming from the headphones port and the left side of my iPhone screen in two seperate sections of the left side. However, I opened an extra line to get my iPhone discount price then once received the new iPhone 3GS I put my other sim card in to keep the same number I've been using. Basically I'd like to know if there is a way of me still being able to swap this for a new iPhone 3GS with no problem? Or..would I need to throw the sim card in that came with the iPhone that I activated it with?? I just want to make sure the warranty will still be in effect and able to receive a new iPhone with no issues. Unless I'm worrying too much and they don't check into sim card issues considering both sim cards have iPhone plans, I appreciate your help! Thank you.