Trying to update a friend's non JB 3.0.1 3G to jailbroken (or even non jailbroken) to 3.1.2. Want to preserve the baseband for options on unlocked and jailbreakable. I created an IPSW from pwnage tool 3.1.4 using the Apple 3.1.2 file (Mac OS X based). Used the simple method, answering non jb'n before and using a official carrier for the 'activate'. Modem version is 04.26.08. Tried 'option' restore method to choose the file in iTunes, and it gives an error that it's not a valid restore file. I thought from reading the Dev's blog site, plus here, plus a few other sites that a 3G can be restored to any version. I know I'm doing some step wrong, or misunderstanding something. Anyone help out? TIA.