Why are my recent imported photos disappearing?

Question

All of my photos imported in the last 2 months have disappeared from my iphotos events. Where have they gone, and is there any way to get them back? Once I import them they show up, but if I quit iphoto and reopen they are no longer there. We just recently sarted to use time machine to back up our system, though I think some of the missing photos predate the addition of time machine.
How can I stop this from happening and how can I recover month's worth of missing photos?

Answer 1

Have you checked the View ➙ Sort menu to make sure the Events are sorted as you expected and looked for the photos that way?
Or use the Search feature at the bottom and choose Date.
Then click on one of the last two months and see what you get:
If none of those find any photos continue with (assuming you're running iPhoto 9):  apply the two fixes below in order as needed: 
Fix #1
Launch iPhoto with the Command+Option keys held down and rebuild the library.
Since only one option can be run at a time start with Option #3, followed by #4 and then #1 as needed.
Fix #2
Using iPhoto Library Manager  to Rebuild Your iPhoto Library
1 - download iPhoto Library Manager and launch.
2 - click on the Add Library button, navigate to your Home/Pictures folder and select your iPhoto Library folder.
3 - Now that the library is listed in the left hand pane of iPLM, click on your library and go to the File ➙ Rebuild Library menu option.
4 - In the next  window name the new library and select the location you want it to be placed.
5 - Click on the Create button.
Note: This creates a new library based on the LIbraryData.xml file in the library and will recover Events, Albums, keywords, titles and comments.  However, books, calendars, cards and slideshows will be lost. The original library will be left untouched for further attempts at fixing the problem or in case the rebuilt library is not satisfactory.
OT