TinyUmbrella has been updated to add support to iOS 4.3.4, But we don’t recommend updating your firmware to this version.
Apple has finally come out with their ‘fix’ for the pdf vulnerability that JailbreakMe 3.0 uses to jailbreak devices. In proper good form, @comex has released a much better* fix for the vulnerability which also incidentally allows you to stay jailbroken 🙂I’ve updated TinyUmbrella to save 4.3.4 SHSHs (as well as the other ones Apple is still signing). So grab the latest if you want to save 4.3.4 for nothing else than for the sake of completeness.
So it would be better if you stick to iOS 4.3.3 and use the fix released by Comex to patch this exploit.
Download TinyUmbrella For Mac and Windows from here.