Cannot restore 4.2.1

[READER84]

Hi, my iphone4 on greenpoison 4.2.1 started playing up and freezing so im trying to restore it again, ive got the firmware file and still have the SHSH files from when i first upgraded it, although my SHSH files are not visible in cydia anymore?!? and will no longer show on TU, I try to restore and all i get is error codes, (1604) ive tried everything i can find online...

Any ideas anyone?

Also is the jailbreak for 4.3.2 unteathered redsn0w stable and working?

Does it have to be re-jailbroken after the phone has powered down?

Thanks

[mexicaninja]

The redsn0w untethered jailbreak works fine. I have not had any issues. You don't have to re-jailbreak every reboot.