hi, i'm italian and i briught usa iphone 1.1.1 unlocked, ok i used guide to 1.1.2 unlock and it' all ok, but when i have installed a program from sources frenchiphone, my iphone blocked so i try to downgrade to 1.1.1 after to 1.0.2 and after this 2 downgrade, now my iphone can only upgrade to 1.1.2.

If i can try to do a downgrade to 1.1.1 itunes gave me an error, i can only install 1.1.2, why?pls help me...