Unnamed/named faces unsticking in few select photos

Question

Please let me know if anyone has experienced this or know why this may be happening.
Out of about 4000 photos, 3 photos if I name the face, click done, and then go back into it, the face is gone (the name of the face as well as the recognition that a face exists in that location). You have to add missing face again, but each time you hit done or go to the next photo and come back, the face you added disappeared. If you add the missing face and don't name it yet and hit done or go to the next photo and come back, still it unsticks/disappears. Naming the face doesn't have anything to do with it.
I tried resaving the photo again as a jpeg, then as different formats, imported again and same issue. I was going to attach or a give a link to this photo, but first modified the photo so the faces are yellow circles with black background (using paint), but then after importing this modified photo, the name sticked. So it seems that overwriting a certain part of the photo allows the names to stick. This is really annoying because the 3 photos are not that old and I would really prefer to face name. The ironic thing is that those 3 photos, each have multiple faces and it's just one face in each of the photos (not the same pictures, taken different times, different people) that doesn't stick. One photo has 3 faces and in the first two it even suggests names and the last one I'll add, then get back to it and it's gone.
Any ideas?
Thanks.
I have iPhoto 09 8.1 using latest leopard.

Answer 1

LN,
Thank goodness I created a backup. I rebuilt from the last automatic database backup and all my faces were gone. I started tagging from new, and then I tried those 3 photos again and again same problem. The tag won't stay on the photo. Other pictures and other people in the photo tag fine. 1 photo is 3 faces and I can only tag 2 of them, and the other 2 photos (different events) only 1 out of the 2 faces it tags. Since rebuilding lost all my faces, I went back to the original library.
I also tried rebuilding permissions besides the thumbnails and tried all over, still same issue.
What is also really annoying is once I blur out the face on the photo so that I can show you what I mean, then the tag stays after I try again. So I can't show an example without revealing other people's faces, which I would prefer not to do our of other people's privacy to use as an example. I wish I knew what was going on or how to resolve this. What's weird is that it is so obvious that these are faces too and can't see anything out of the ordinary with these.
I tried one other thing that is interesting. If I reimport that picture and FIRST tag the face that unsticks, and hit done, then it stays. Then if I go to faces, I see the picture, but it's weird because in all the thumbnails where the face is the focus of the picture, this the face is almost half off because the face pictures is basically the center of the picture. If you go back to the photo, the face is still tagged, but in the thumbnail it's like it takes the center of the picture and zooms into that, which is basically space between two faces. Then I tag the other face that normally sticks in the photo, and then that is when the original unsticks again. So another thing I've noticed is that it sticks only if you tag only one face in the photo even though in the faces thumbnails it looks a bit off centered then not based on tagging. If you tag this face and exit iphoto, it sticks , but then leaves a grey thumbnail. What weird behavior. I wish apple would have an answer to this.