"Last Import" photos not in "Last 12 months" after upgrading iPhoto library

I have iphoto version 9.3.2

This week, I got a message on iphoto "Your photo libary will not be readable by previous version of iPhoto after the upgrade. The photo library needs to be upgraded to work with this version of iPhoto. ......"

So, I selected "Upgrade".

After I upgraded my iphoto library, I have 2 new problems that I am aware of:

When I import new photos to iphoto, they show up in the "Last Import" folder but do not show up in the "Last 12 Months" folder. Then, when I import even more new photos, the photos from the previous "Last Import" disappear and still do not show up in the "Last 12 months" folder. All of the rest of my library that was there before I performed the upgrade is still there as previously.

Just for kicks, I imported the "missing" photos again, but iPhoto says "would you like to import the following duplicate photo?" This, of course, indicates that the photos are in iPhoto. They just are not showing up in the "last 12 months" folder.

In addition, the photo for my desktop disappeared and now shows the default image of the galaxy. I only indicate this issue, as it may help in figuring out my first problem noted above.

Anny suggestions? It seems like it should be an easy fix!