I already purchased a FACTORY UNLOCKED IPhone 4 in Canada (MC604C) but when I update to IOS 5.0.1, it locked again. As far as I know, when an Iphone is factory unlocked, it will be unlocked forever no matter how many times I update the version. I called Apple. They admit that my IPhone was factory unlocked and assist me with some easy steps like putting in and out the sim card, turn off the phone, ect. But my IPhone still required a valid sim card from supported carrier to activate. The point is, why do I need a valid sim card from Canadian carrier since my IPhone is factory unlocked and supposed to work with ANY SIM? I asked Apple. They know the problem. They confirmed that this IPhone was factory unlocked and the only way for me is to CONTACT THE CARRIER WHICH PROVIDE THIS IPHONE. "If this was unlocked and now locked again, call the carrier to unlock it. Apple can't do it. You can't do it. Only the retail store or the carrier which provide Iphone 4 can so it". That's what he said. But the point is I'm not in Canada now. My carrier was FIDO. And I have paid $50 to unlock it. Does it mean that I'll have to pay another $50 to get it unlocked again? My old version before updating was 4.3.2, baseband 03.10.01. Can anyone help me with this problem? Can someone in Canada call FIDO service to work this out for me? Please... My serial is: 88118TSHDZZ Thank you.