Have you confirmed the problem in iPhoto or just from iWeb and the Media Browser window. If it's only the latter open iPhoto and make sure it is either all OK or missing the photos from Jan 2011.
If it does appear to be missing those photos try the following: make a temporary, backup copy of your library if you don't already have one (Control-click on the library and select Duplicate from the contextual menu) and apply the two fixes below in order as needed:
(This is assuming you're using iPhoto 8 or earlier. If you're using iPhoto 9 let us know)
Launch iPhoto with the Command+Option keys held down and rebuild the library.
Select the options identified in the screenshot.
Using iPhoto Library Manager to Rebuild Your iPhoto Library
- Download iPhoto Library Manager and launch.
- Click on the Add Library button, navigate to your Home/Pictures folder and select your iPhoto Library folder.
- 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
- In the next window name the new library and select the location you want it to be placed.
- 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 but not books, calendars or slideshows. The original library will be left untouched for further attempts at fixing the problem or in case the rebuilt library is not satisfactory.
If that doesn't help and you need to use Time Machine go to your Pictures folder and enter Time Machine. Go to yesterday's date, select the library and restore. If you have the space on your hard drive select the option to Keep Both versions just in case the backup isn't good. Then you can go back in time a bit at a time till you get the newer versions (if at all).
I'd try repairing your current library first.
The problem was that I lost IPhoto library (can't imagine how). I've got it back and now my images seem to be back. But I would like to manage IPhoto better, so if there's another option please let me know.
I am using IPhoto version 9, so the command/option open didn't work.
I couldn't load the IP manager as I have OS10.5.8
Thanks so much