Hi, I purchase an iphone off ebay to replace my wife's which was stolen. I had unlocked that one to work with t-mobile. Now for this one, I keep on getting a 1600 error or 21 error message. Here are my settings: 10.5.5, itunes 8 Here's what I've tried: Using recovery and dfu modes. Using the previous custom ipsw fie from the old iphone but still get the messages. I've used pwnage 2.0.2 with 5A347 ipsw as well as pwnage 2.1 with the 2.1 ipsw, but still get error messages. But no matter what, I can still manage to restore the iphone to the original 5A347 ipsw. That seems to save me from a nervous breakdown!! Do you have any ideas. Please help! Thank you!