UltraSn0w Fixer has been updated which now supports iOS 5.1.1 and can unlock iPhone 4 and iPhone 3GS on the following basebands —
If you want to unlock iPhone 4,iPhone 3GS on iOS 5.1.1 with UltraSn0w Fixer then -
1. Launch Cydia and add the 3rd party repository UltraSn0w Fixer for 5.1.1 >> Go to Manage >> select Sources.
2. Tap Edit button and add http://repo.iparelhos.com and then press Add Source.
3. Go into the iParelHos repo section, find UltraSn0w Fixer for 5.1.1 and install it to your device.
4. After installing UltraSn0w Fixer, go to Search tab of Cydia and search for UltraSn0w.Install UltraSn0w and reboot your device.
Your iPhone 4/iPhone 3GS is now unlocked on iOS 5.1.1 with UltraSn0w Fixer.