TinyUmbrella has been updated to version 5.10.03 by Notcom. The new version includes support to save SHSH blobs for Apple TV iOS 4.4.3 which you may need for downgrade or do an untethered jailbreak.
You can download tinyUmbrella 5.10.03 from following links.
TinyUmbrella 5.10.03 for Windows
TinyUmbrella 5.10.03 for Mac