If you are not seeing the project in the Library tab of the Inspector make sure you are not filtering it out here:
You should also look in the Projects view to see if you see it there.
How did you import the images? If you did it any other way then through the Import pane then the settings in the Import pane do not apply.
Where are you looking for the project? You are importing "referenced", right? DO I understand you correctly - the Finder and the Photos view are showing your project, but it is not listed in the projects list?
- Are your images by any chance in the Trash? Have you checked there?
- Do you have your "Projects" hidden? You will see no projects at all, if you collaps the Projects list in the library by pressing the hidden "Show/Hide" button to the right of the caption "Projects". Nearly all parts of the Library Inspector panel can be completely hidden this way - Albums, Projects, Recents, Web.
The "Show/Hide" controls will appear, when you hover the mouse over the hidden controls.
Reimported from the hard drive and it didn't create the project again, though the images now appear under Photos. Still no project. Second import and it didn't create a project. Tried to create a project and it didn't work.
Are the projects also missing from the "Projects" view in the upper part of the library inspector, or only from the projects list?