I'm also seeing this error when trying to import an aperture library. I have two aperture libraries and the first one imported ok (took a while) but the second one gives me this "name is not unique" error. I've subsequently opened it in aperture and renamed then even deleted the aperture folder with the name it reported. That did not help. I also had aperture rebuild its database, which did not help. And I tried the "import photos as referenced" mentioned above which also made no difference. Suggestions?