I just bought an iPhone 4 off a friend. I noticed the speaker is messed up, it has a muffled sound to it. I know because I compared it to my iPhone 4 and there was a difference in the sound. I was wondering if Apple would replace my iPhone since it's still under manufactures warranty? The 1 year warranty doesn't expire until 2012 and would they still replace it even though I'm not the original owner?