iPhoto library rebuilt OK, but corrupted again when re-opening iPhoto.
imported photos from iPhone 5 today into iPhoto. Was able to view and edit OK then at one point it froze and had to close it. When I tried opening iPhoto again I got a message that library was corrupted or unreadable. Performed iPhoto first aid and got the same message for all choices except for the rebuild. Did a rebuild of the library and all photos appeared in iPhoto as before. BUT, when I closed iPhoto and reopened it I got the same error message. Why does iPhoto do a proper rebuild but then becomes corrupt again when you re-open it?
I have an older back-up of iPhoto library (from a few months ago). I made a backup today, but suspect that library may be corrupted because when I restored it, I had the same issue. I haven't tried restoring the older library yet as I was wondering if there was a way to keep the rebuilt library rather than restoring an older version.
Mac Pro, OS X Mountain Lion (10.8.2), iPhoto