With the iOS 4.3 update released for iOS devices, the jailbreak developers got busy scouting for exploits. Meanwhile sn0wbreeze developer who goes by the online name – iH8sn0w earned some brownie points with early tethered iOS 4.3 jailbreak. Now he has managed to come up with a tool that will unlock only those iPhone 3GS devices that were updated by retaining the iPad 6.15.00 baseband. The tool has been developed by iH8sn0w along with the TinyUmbrella developer – msft_guy.

As per iH8sn0w, the ultrasn0w fixer feature basically runs the older ultrasn0w unlock for the users who wish to update the iPhone 3GS and iPhone 4 with the new iOS 4.3 update. However, in the case of iPhone 3GS one has to use the iPad 6.15.00 baseband while updating with iOS 4.3 and use sn0wbreeze 2.3 beta 4 - Hotfile.com: One click file hosting: sn0wbreeze-v2.3b4.zip to jailbreak the iPhone 3GS. Then the ultrasn0w unlock needs to be installed by adding http://repo666.ultrsn0w.com]ultrsn0w.com to the sources in the Cydia App post jailbreak.

The developer confirmed that the ultransn0w fix for iPhone 4 is under testing and would be included in the next beta of the sn0wbreeze 2.3 tool.

Msft_guy isn't the same person as semaphore (TinyUmbrella author)

ih8sn0w's jailbreaks aren't necessarily bad, but most of the serious tweak developers have been very clear that they aren't updating their tweaks for 4.3 until a jailbreak is released that includes proper patches either made by comex or of equal quality.

I would strongly advise jailbreakers and unlockers avoid 4.3 until either iPhone dev team or chronic dev team release a proper jailbreak.