Open TinyUmbrella and click START TSS Server, then put iphone into DFU and open itunes. select your phone in the left pane of itunes and do a SHIFT + RESTORE and select your ipsw. let it run. You may get a 1013 error, if so the open FixRecovery and use this to kick it out Recovery. TRICK here is your iphone again has to be in DFU mode for it to work. Put the FixRecovery folder on your desktop and make sure the zlib1.dll file is in that folder as well.
After it kicked out set your phone up as new and use Redsn0w to jailbreak again.
This is what i just did last night to restore my iphone 4 4.3.3