Basically I have had the ' Invalid SIM card ' message instead of the 'Orange 3G' label on my Iphone 4s several times. I bought it from Carphone Wharehouse on 23rd October 2011. I returned to the store only to be told that this is a warranty issue and is not covered by the insurance. I was told to make an appointment with an Apple Store and get a new one from them as the Apple Store would do ' diagonistic tests' on it. Any ideas as to the ' Invalid SIM card' message please?