Smart Album Keyword Bug

I have a library of 17,440 “Referenced” photos, grouped across multiple projects, none of which contain more than about 400 photos. Prior to importing these images into Aperture, I had already keyworded all of them; the keywords are embedded within the image files.

707 of these images have the keyword “Cruise_Ship” (photos of or on a cruise ship). I then created a smart album with a SINGLE filter, “Keyword = Cruise_Ship”. I have no other filters selected, I have no other keywords selected in the keyword filter, and at the top of the keyword filter, I have selected “Include ALL of the following”.

However, instead of the 707 expected images, this smart album actually displays 5336 images. I have verified, via the metadata browser that in fact most of these images DO NOT contain the keyword “Cruise_Ship”.

So, I tried the following (in order). After each step, I once again checked the contents of the smart album, and in each case it displayed 5336 images instead of the correct 770:

Repair Database
Repair Permissions
Rebuild Database
Reboot Computer
Rebuild Database

As one last attempt, in the Keyword HUD, I renamed the keyword “Cruise_Ship” to “CruiseShip” (no underscore). The HUD correctly indicated that that keyword was used in 707 versions. I then in fact changed the keyword in those versions. I then created a NEW smart album, with the only filter being “Keyword = CruiseShip” (again no underscore) and once again the smart album incorrectly displayed 5336 images.

I am using Aperture 3.0.3.

I’m out of ideas...