My friend has an iPhone 4 which has stopped working ('SIM not recognised'). His previous iPhone had a faulty mic and was replaced after 6 months. Although this current iPhone 4 is less than 12 months old, my friend seems to think that, as it's a replacement, the warranty just carried on from the faulty first phone and has therefore expired. Surely the year's warranty should reset with the replacement handset? Anyone heard of this?