Yesterday, @MuscleNerd gave us a heads up for today’s Ultrasn0w update which has just gone live on Cydia. The latest update to Dev-Team’s carrier unlocking tool is Ultrasn0w 1.2.4 which is now fully compatible with iOS 5.
Those who have updated to iOS 5 using a custom .IPSW file created with recent Redsn0w version can use the latest Ultrasn0w to unlock the following supported basebands on iPhone 3G/3Gs/4:
Before you proceed, take a look at these important instructions by Dev-Team:
Note: there’s a special “trick” that iPhone3GS owners with baseband 06.15 need for iOS5. During the new setup screens you see when you start iOS5 for the first time, you’ll be asked about Location Services. Be sure to select “Disable Location Services” when asked! Later on in the setup, you’ll have the chance to turn on Location Services again when asked if you want to use “Find my iPhone”. It’s fine to turn it back on at that point, if that’s your desire (or you can always go in and enable it in Settings.app).
Also, some iPhone3GS users with the 06.15 baseband may have tried to install iOS5 using a stock IPSW (even though you should never ever try to use a stock IPSW if you’re an ultrasn0w unlocker). If you did try this, your baseband is probably in an inconsistent state, and you’ll need to reflash the 06.15 baseband again (using redsn0w). Be very careful if you use redsn0w to reflash the iPad baseband — don’t interrupt the process! And please avoid using stock IPSWs in the future 🙂 Unlockers should never go near stock IPSWs.