Earlier this month Notcom released TinyUmbrella 4.21.08 to support Verizon iPhone and now TinyUmbrella 4.21.11 is being released.
This new version fixes few bugs found in the earlier version and it solves the bandwidth usage problem.
According to Notcom Official blog-
I just pushed a smaller, trimmed-down version of TinyUmbrella. This change had to take precedence over the other things I was working on for TinyUmbrella because the bandwidth usage was insane. Now that this is out of the way, I can go back to the 4.2.1 recovery kick out issue. Have a great weekend folks!
TinyUmbrella help users to save iOS 4.2.1 SHSH blobs.