I decided to update the software on my iPad 2 this evening. I have updated software on this iPad previously without any problem. It's not jailbroken or anything. When I hit 'update' it said "verifying update" for a few seconds, then the screen went black and showed a picture of the usb cable and the iTunes logo. I had never seen this screen before. When I plugged it into iTunes, it told me something like "this iPad must be restored to factory settings before updating."...