Some info for unsuccessful folks...I went to 1.1.3 restored via iTunes which locked everything inc my SIMs back to 1.1.1 unlocked, activated and jailbroken.
From a 1.1.1 unlocked/jailbroken US iPhone here in UK on o2 Simplicity card, I got to the very last stage when something went wrong. Maybe it was one of the apps I had on there, who knows.
Anyway, after going wrong, I restored to 1.1.3 then followed the downgrade 1.1.3 guide. Despite having the "Not valid SIM" message back on 1.1.1 and 1.0.2, I still managed to get everything back working (yes the phone included), jailbroken and unlocked/activated again on 1.1.1 where I think I'll stay.
edit: I used iTunes 7.6 on Leopard and the original, unactivated AT&T SIM throughout.
From a 1.1.1 unlocked/jailbroken US iPhone here in UK on o2 Simplicity card, I got to the very last stage when something went wrong. Maybe it was one of the apps I had on there, who knows.
Anyway, after going wrong, I restored to 1.1.3 then followed the downgrade 1.1.3 guide. Despite having the "Not valid SIM" message back on 1.1.1 and 1.0.2, I still managed to get everything back working (yes the phone included), jailbroken and unlocked/activated again on 1.1.1 where I think I'll stay.
edit: I used iTunes 7.6 on Leopard and the original, unactivated AT&T SIM throughout.