I looked around on the forum and tried following what other people have said about not using TU when updating, and having host files point to apple servers. I believe I have done all these and still get a Error 11 when using TU also. I have backed up all my SHSH and have them sent to cydia as well as having them locally on my computer. My itunes is updated to the most current version also. I am trying to go from 4.3.1 to 5.0.1 on my iphone 4. I created a custom IPSW and followed the other tutorials but when unpackaging it, it gives me that error. Phone was also in pwned DFU mode when attempting update from custom IPSW. My phone is currently unlocked and jailbroken also. my host files have these lines in them 127.0.0.1 gs.apple.com #18.104.22.168 gs.apple.com Anyone have any other suggests it would be greatly appreciated.