iPhone Dev-Team has released ultrasn0w 1.2.7 unlock to support iOS 5.1.1 unlock on old basebands.
- ultrasn0w unlockers must stay away from redsn0w! Use only a custom IPSW to update to 5.1.1 , to avoid updating your baseband. like Sn0wbreeze or Pwnagetool .
- ultrasn0w has been updated to v1.2.7 to be compatible with iOS 5.0.1 and earlier (the ultrasn0w update does not include any new baseband support!). Please reboot your iPhone using the normal “slide to power off” swipe after installing ultrasn0w 1.2.4 .
- The supported basebands for the iPhone 3G and 3GS are 04.26.08, 05.11.07, 05.12.01, 05.13.04, and 06.15.00. The baseband supported for the iPhone4 is 01.59.00.