http://blog.iphone-dev.org/
Make sure you reboot the iPhone after doing anything in Cydia. If you got an invalid SIM response that means ultrasn0w didn't take and you should try reinstalling.
If you got "Call Failed" messages on T-Mobile, well, turn airport on and off and reboot lots. All in all, keep rebooting until it works?
Make sure you reboot the iPhone after doing anything in Cydia. If you got an invalid SIM response that means ultrasn0w didn't take and you should try reinstalling.
If you got "Call Failed" messages on T-Mobile, well, turn airport on and off and reboot lots. All in all, keep rebooting until it works?