Important announcement for iPhone3Gs users on 06.15.00 baseband updating to iOS5
Along with the release of iOS5 compatible Ultrasn0w 1.2.4 yesterday, the iPhone-Dev team added a special note for iPhone3Gs users who have updated to the 06.15.00 iPad baseband or plan on doing so. Just like any other unlockers, 06.15.00 baseband users should NEVER update to a new firmware using a stock firmware. Even though the iPad baseband cannot be upgraded, trying to install a factory firmware may screw up the baseband.
If you have already tried updating to iOS5 stock firmware on your phone with 06.15.00 you will probably have to reinstall the iPad baseband. For those who updated with a custom iOS5 firmware, there is a special process you will need to do after restoring 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.