I have an iPhone 4 jailbroken on ios 4.3.1. I am trying to upgrade it to ios 5.0.1 but all I get is error 1600. I have put it into pwnd DFU mode with both RedsnOw and jREB, but still get same error. My hosts file is pointing gs.apple.com to Cydia (also tried using Tinyumbrella TSS server). I have tried using redsn0w to stitch my shsh blobs and ipsw together, but still get error 1600. I am really frustrated with this! Any ideas?