I am running Aperture version 3.3.1 on OSX 10.7.4 on a MBP Retina. When I try to update one of my vaults, it gives me a warning that the "n" number of images imported by reference will not be a part of this vault.

When I select all the images in my library and select
Locate Referenced Files ...
it returns 0 results.

I also have created a smart album for referenced files and that is empty. Am I trying to find my referenced files incorrectly? My intention is for all files to be in my library and have none referenced.