My cousin bought an iPhone 4 from someone this weekend. The guy who sold it said its a factory unlocked phone (its bought from australia) but my cousin didnt have a micro sim handy to check it at that time. Anyways, he bought it and now it says "invalid sim" when he tries to use it with any sim (tried with a micro sim and a regular sim cut down to fit in an iphone 4). To the best of my knowledge, Apple only sells unlocked iPhones in Aus, so I'm not sure how can this be a carrier locked phone? I'm completely confused and not sure what I should do here. I dont even have the original sim which it came with so cant try restoring it as that'll turn it into a paperweight if it doesnt activate after the restore. Any idea why this isnt working? Did the seller dupe my cousin? In which case, is there nothing else which can be done to get it working with other sims except waiting for the 4.2.1 unlock?