I updated iTunes, and successfully updated my iPhone software. Now I'm trying to do the same with another iPhone that also syncs music/video with the same iTunes. The second iPhone usually has a name like "Johnny's iPhone" but now it just says "iPhone" and when I try to update it, it says "An error occurred while backing up this iPhone (-35) Would you like to continue using this iPhone without the backup?" So I always cancel it. Can you only update one iPhone per computer?