When updating my Iphone 3G to ios 4.2.1 I get a alert saying: your sim card is not compatible, to activate your iphone please go to a operator to get a compatible sim card, why is this happening? how can I get my phone back??

OL. Last time.

YOU CAN NOT USE THAT PHONE. Not unless you intend to move to the U.S. and get service from AT&T.

You can try asking AT&T YOURSELF if they will unlock it using the web form that's already been linked to here.

If they will not, or if it does not work because of damage done by the original jailbreak, then you are out of luck.

The phone was jailbroken or hacked when you bought it, else you would not have been able to use it.

Jailbreaking, hacking, and jailbroken and hacked devices can NOT be discussed here per the terms of service.

There is nothing more we can say.

Text removed; Tim beat me to it again.

Message was edited by: varjak paw