We are building a house and taking over 400 photos a day to document the progress. Unfortunately, we noticed that several days of photos have disappeared. So we went to our Time Machine back up only to find that the 3 days in question are there, meaning the computer backed up for those days, but not the photos! We get the thumbnails which disappear quickly after they load onto the screen. I've noticed that others have had similar problems as recently as mid 2013, but no solutions. My wife kept tinkering with iPhoto and miraculously have retrieved 111 of the lost photos, even as they don't show up in the folders within the "package contents" of the iPhoto library. Any ideas?