A little backgroud, I have an iPhone 3g on AT&T, 2.2(jailbroken) I'm using Pwnage to create custom ipsw. for 2.2.1. After Pwnage was done it wanted me to put the phone into DFU as usual, but after DFU, itunes did not recognize, error(2001). Closed itunes and killed itunes helper and restarted itunes. itunes the recognized the phone but gave error(1600) when attemping to install custom firmware.(already installed the DFU "fix" on OS 10.5.6) Closed itunes. Rebooted phone, started itunes and hit "Option" restore. Selected the custom firmware and itunes installed it fine.

I have 2 questions for the MMI community:

1. If you restore using the "Restore" button on itunes is there any data not flashed, like if you use the "Update" button?

2. If using the "Restore" button is the same as DFU mode why then go throught the trouble of DFU mode of your not Unlocking?