I have the factory default 2.1 fw. I downloaded the jailbroken Cfw that was posted online. When i to put my phone into DFU mode, it says on iTunes that the phone is in recovery mode, not DFU. I have followed the instructions exactly and it still apparently is entering into recovery mode. When I tried to Shift+Restore to the Cfw, it gives me the error 1600.
Did they change the way to get into DFU when they put out the 2.1 fw?
the way to tell whether you're in DFU or not is by your iphone's screen. when you're in DFU mode, your phone's screen will be completely black/blank as if it's been turned off. iTunes still calls it recovery. If you're in recovery mode, you should see the usb cord and an itunes logo.
from what i know is you actually want to be in recovery mode and not DFU mode. people seem to get that error code when the phone is in DFU mode, so try recovery and see what happens