The newest version of TinyUmbrella, the application that offer you to recieve backups of SHSH blobs (ECID SHSH) has been launch in-order to support iOS 4.3.1.
On his blog, Semaphore-developer of TinyUmbrella revealed the launch of the new version:
TinyUmbrella now supports 4.3.1 for the relevant devices. Currently only iPhone 4 for verizon does not have 4.3.1 support (as there is no 4.3.1 available for the verizon iphone). Enjoy!
Please remember that if you have jailbroken your device then Cydia will instantly store the SHSH blobs (ECID SHSH) as when you launch it. So you don’t need to use TinyUmbrella to take a backup.