why does new phone say invalid SIM?

one1

Member
Bronze
Sep 20, 2007
53
0
6
Signal Mountain, TN
#1
my buddy bought a new iPhone and he wasn't getting good service so he sold it to me a week later. It is a brand new 1.1.3 phone that I restored to 1.1.1 and jailbroke using the keypad trick and jailbreakme.com

For whatever reason when i restored it today to hook it to att service
via iTunes, both the phone and the iTunes say invalid sim. I tried three brand new sims and all do this.
it has never been unlocked and the numbers all match on the phone.

Any help please?