My iPhone is already j/u/a Tmobile-US.
Installer on the phone is not working anymore. It goes back to main iPhone screen as soon as I click it's icon.
I guess I upgrade it to version 2.0 which they say does not work on 1.0.2 firmware.
Can I just use iLiberty to install Installer 1.2 to overwrite the old one? Should I turn on the iTunes in the meanwhile?