Thumbnails visible for a split second and then disappear. Able to print thumbnail, but not find it or the master anywhere. They display as a triangle with exclamation point. Any suggestions? Tried to rebuild to no avail.

All this occured when I updated to iPhoto 11 just after my upgrade to Mavericks. I tried Old Toad's suggestions of rebuilding and using iPhoto Manager, but still cannot find them. Strange that I can see the thumbnail for a split second, but even thumbnail will not pop up in search for photo. Any chance masters and thumbnails may have changed names and found a different home?

Unfortunately, Time Capsule was somehow corrupted as well. Cannot access anything older than when the update to iphoto 11 occurred.