I've had this problem for a while but as of lately it has started to become annoying. So the problem is that I can't restore (or update) my iPhone 4 with my MBP but I CAN do it when I use my brother's MBP. And I have no idea why! In the first few months of having the iPhone there were no problems, but starting with 4.3.1 and up, every time I'd try and update/restore - I'd get an error message that the phone was sent to recovery mode and that I should connect it to iTunes. After connecting it to iTunes and trying to restore it again, I'd go through the same process and end up in the same place. It was just going in circles. Then I took it to my brother's MBP, plugged it in, did a restore and voila - no problems whatsoever! At the emergency screen, I'd take it back to my MBP and restore it from my backup and that would work fine. But, sometimes I might not have access to another Mac, I mean most of the time I won't have access to another Mac other than my own, so how do I fix this? MBP is running all the latest software, as is the iPhone as well. iTunes is up to date.