Photos Missing from Search and Smart Album Results

I recently converted from iPhoto to Photos and the transition seemed to go smoothly enough. However, I've noticed that, when searching for certain pictures using either the search function or smart albums, some pictures don't seem to be included in those queries even though they are definitely in the photo library.

For example, we've gone on a few trips to Disney World. The ones from this year show up fine in both search and smart albums using any keyword, location information, etc, but the ones from 2007 only show up in search under the 'Disney World 2007' album that I created and can't be found using location information, keywords, people, etc. I checked to ensure that the location information is identical to those pictures taken this year. In addition, all faces and keywords have been updated to be consistent with photos taken this year as well.

I just tried to the Repair Tool and it doesn't seem to have done anything.

Any thoughts?