Notcom, developer of TinyUmbrella has posted a reminder message for all of jailbreak community to save SHSH blobs for iOS 5.0.1, and there are high chances that with the release of upcoming iOS 5.1 Apple does not allow to save SHSH blobs for the old firmware.
According to Notcom’s official blog:
With the quiet time between jailbreak and iOS version, make sure you get your SHSHs saved. I’ve been working on the TinyUmbrella rewrite (albeit sparingly due to real life demands). It’s important to make sure you have your 5.0.1 SHSHs tucked away safe. There is no guarantee that we’ll have things this good again.
You can grab TinyUmbrella for Windows and Mac through link below.
Download TinyUmbrella 5.10.06