As expected, iPhone Dev team has released an updated version of Ultrasn0w – v1.2.1 to fix the iOS 4.3.1 compatibility issues and to also the signal bar issue reported by users who had jailbroken their iPhone using PwnageTool, Redsn0w or Sn0wbreeze for iOS 4.3.1. Ultrasn0w 1.2.1 for iOS 4.3.1 currently supports iPhone 4 baseband 01.59.00 and iPhone 3GS basebands 04.26.08, 05.11.07, 05.12.01, 05.13.04 and 06.15.00. We’ve pushed out the 4.3.1 compatibility fix for ultrasn0w in Cydia — it’s now at version 1.2.1.  If you’re not already at 4.3.1 and you need the unlock, please be sure you understand how to get to 4.3.1 using a custom IPSW that doesn’t update your baseband. This isn’t a new unlock! It’s to allow those who are already unlocked to use FW 4.3.1.  It also fixes the signal bar issue for those who aren’t using the unlock but retain an older baseband intentionally. AFTER INSTALLING ULTRASN0W 1.2.1, PLEASE REBOOT YOUR iPHONE using the normal “slide to power off” swipe.  T-Mobile users in the USA also should disable 3G mode in Settings->General->Network. However, it should be noted that this release of Ultrasn0w is not a new unlock for iPhones with newer basebands, it is ONLY compatible with basebands 01.59.00 / 04.26.08 / 05.11.07 / 05.12.01 / 05.13.04 / 06.15.00. After installing UltraSn0w 1.2.1 you should reboot your device by using the normal power button and “Slide to Power Off” swipe. USA T-Mobile users need to disable 3G mode in Settings:General:Network. To upgrade to iOS 4.3.1 without upgrading your baseband you can use the guide below: You can find our UltraSn0w unlock tutorial here. We will provide more info as it is made available, as usual, stay tuned by following us on Facebook, Twitter and/or by subscribing to our RSS Feed. Authors:

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