So I have an iPhone 3Gs that I just sold on eBay. It was unlocked to 4.0.1 and the buyer asked me to update to 4.1 unlocked. I figured no problem. I loaded the pwnage tool and created the IPSW but was never able to load the custom IPSW. I connected it to tinyumbrella and have my blobs saved to 3.1 before I attempted to update it. My baseband is 05.13.04-6.4_M3S2.

Any ideas whats going on? I am stuck in perpetual recovery mode. I have tried to downgrade back to 4.0.1 and the firmware doesn't fully load. It is just stuck about 75% of the restore cycle. Any help would be appreciated. I would like to ship to the buyer today/tomorrow.

Each time I get into DFU mode and attempt a custom restore, I get error 1600.

Thanks folks