I have an unlocked iPhone 4 on 5.1 that I used SAMs Pref to unlock back in April, while it was already a tethered JB with Redsnow. About once a month I do a tethered reboot with Redsnow, and never have any issues. Yesterday, I installed BiteSMS from Cydia, and it needed a reboot to finish the install. I tried to do the tethered Redsnow boot, and keep getting an error when attempting to get into DFU mode. "Missing Keys.Plist data for this build" The phone is still unlocked on Tmo, but mail and Safari crash. I can make calls and text, though. I backed up from a previous version in iTunes, no change. Any help is appreciated to get it working correctly.