iPhone 4 and iPad 2 owners who found iOS 5.0 or iOS 5.0.1 not to their liking and attempted to downgrade their devices to an earlier version of Apple's operating system probably got stuck in a recovery loop.
Luckily, NotCom has released a downgrade tool that solves this problem: TinyCFW. TinyCFW lets users revert their jailbroken iPhone 4 or iPad 2 to the old iOS 4.3.3. using SHSH blobs, assuming that these have been saved in the past.
As the developer explains, this tool is supposed to modify an existing ipsw for an iPad 2 or iPhone 4, regardless of the GSM/CDMA capabilities and at the same time it will modify the ipsw to update the baseband to the latest one.
TinyCFW will create an ipsw that can be used with TinyUmbrella and iTunes to restore to a version of iOS for which the user has SHSHs. TinyCFW's creator warns that this tool wasn't meant for public release, it was initially created just to help out a friend, and it is an early version.
Also it should not be considered a jailbreak solution or a tool designed to protect the baseband or one that will restore the troubled devices to any firmware. TinyCFW doesn't support iPhone 3GS, iPhone 3G, iPad, or iPhone 4S.