As promised, Semaphore has released TinyUmbrella (FixRecovery) for iOS 4.3 which can now kick all those iDevices out of recovery who are stuck in infinite recovery mode loop after iOS 4.3 restore. According to Semaphore, the new version of TinyUmbrella (FixRecovery) is based on Chronic-Dev Team's GreePois0n tool and it can be used to preserve iPhone 4 01.59.00 baseband.
For those who don't know, upgrading to iOS 4.3 using TinyUmbrella or Saurik server leaves you in infinite recovery mode loop. This is due to an extra baseband protection introduced by Apple after iOS 4.2.1 to discourage people from upgrading to newer firmwares while preserving their basebands.
Usage of TinyUmbrella (FixRecovery) is fairly simple. Just download stock iOS 4.3 IPSW for iPhone 4 from here and TinyUmbrella from here (Win | Mac). Click on Save SHSH button and then start TinyUmbrella's TSS Server. Once TSS Server is started, restore stock iOS 4.3 IPSW with with iTunes. When you get 1013 error, use TinyUmbrella (FixRecovery) to kick your iDevice out of recovery mode loop.
Tutorial: Update iPhone 4 to iOS 4.3 while Preserving 01.59.00 Baseband [How-To Guide]
Update#1: Some users reported that they are unable to use TinyUmbrella (FixRecovery) for iOS 4.3 because of some missing zlib1.dll error. To fix this error, download zlib1.dll from here and place it in same directory in which fixrecovery43.exe is present.Contact Us for News Tips, Corrections and Feedback