Sim Card Not Recognized after restore

[gideon00]

I did a recent restore after exchanging my iPhone at an apple store. I am a US ATT customer. No hacks. Now itunes will not recognize my sim. The sim works fine in other phone. any ideas????

 

[jmann]

Try doing a restore, and make sure you are updated to 2.2.1. Also if the problem persists I suggest going here and scheduling an appointment to have it checked out. They will hopefully replace it.