Redsn0w 0.9.8b7c Fixes Error 1015 During 4.3.5 Firmware Restore
If you are one of the iPhone3Gs users that has updated your baseband to 06.15.00 in order to unlock, you may have realized that it is not possible for you to do a factory restore in iTunes. This is because the iPad baseband causes what is known as a "baseband panic" when you try to restore. The iPhone is not supposed to be able to run 06.15.00 so it causes iTunes to error out. Because of this, the only way to restore using the iPad baseband is to create a custom firmware using Sn0wbreeze or Pwnage Tool. Of course, neither of these tools support 4.3.5 so until now it has been impossible to restore on 4.3.5 if you had the 06.15.00 baseband installed.
Yesterday, the iPhone Dev-Team released Redsn0w 0.9.8b7c which allows 3Gs users on the 06.15.00 baseband to restore iOS 4.3.5 on their devices without getting an iTunes error. This version of Redsn0w has a built-in fix-recovery that allows you to bypass the iTunes error 1015 that occurs when restoring a firmware on the 06.15.00 baseband.