Imports to iPhoto '11 disappearing on Mountain Lion OS X 10.8.2
I have: MacBook (late 2008), OS X 10.8.2, iPhoto '11 9.4.2
Some of the Events that I have uploaded for December 2012 and so far for 2013 (some have been edited), are empty - only a palm tree icon is there, and the event title itself.
Some of the Missing (edited) Events I had Exported to my desktop for ease of uploading online for development. Some that have disappeared have not been edited at all, and were there waiting for me to edit them (Yes, I still have the originals on an SD card). When I import the photos back to iPhoto, some photos said that they are duplicates and asked if I wanted to replace the existing versions of the pictures. I said yes. On others photos, it did not ask this question.
I've deleted blank events, re-imported, etc. It seems that if I add an event and close iPhoto, it stays.
I have gone through this several times and it is very frustrating. I have about 14000 pics on my laptop (and they are backed up except the recent photos). Sounds like something is corrupt.
What can I do to fix this issue?
MacBook, OS X Mountain Lion (10.8.2)