I have just discovered a problem in iPhoto.
I have several older libraries of photos, most of which contain photos which have been modified in iPhoto or anther program, usually Elements.
Today I opened one of the older libraries, and was greeted with a notice that the library needed to be updated to use with the current version of iPhoto (9.2.3). I allowed iPhoto to do the update, which appeared to take all of 3 seconds. The library then opened.
Everything seemed ok at first. However I soon discovered that when I made any edits to a photo, and allowed the program to save them, that is was no longer possible to Revert to Original. I then investigated several previously modified photos in the library, and well as some which had not been previously modified. The vast majority could not be reverted to the original, but an occasional one could.
I them replaced the files with new one from a year or so ago, using Time Machine. Again I could not open the file without update, and when updated, the previously noted abnormal behavior recurred.
Finally, I opened another library (newer). This did not require update, and the Revert to Normal Command appears to operate normally.
Does anyone have an idea what is going on?
By the way, I also tried rebuilding the libraries, with no help.