I got my iPhone from Japan and I decided to open line and Jailbreak it to a local Jailbreaker. Before I done that, I updated from iOS 4 to iOS 5. He downgraded my iPhone to ver 4. Then I decided to restore and update my iPhone because it won't let me download apps from Installous. ( I wanted to unjailbreak my iPhone) Then during restore, it asked me to activate. I don't have the original sim. I am using my sim. And it says that there's no sim card installed in the iPhone your'e attempting to activate. Why is this so? Because during I had my phone jailbreaked, I can send messages through my iPhone. Please help