Currently Being ModeratedJul 25, 2012 3:16 PM (in response to Jim Bridger)
I believe this is how it always has behaved. Even with "Do not..." set, the photos will come up to be imported. If you then import them into a project where those photos are already saved, Aperture just won't re-import the ones that are already there.
You don't get an indication in the import dialog that the files are already in your library.
Currently Being ModeratedJul 31, 2012 6:07 PM (in response to Aye Es Oh)
Not sure abot JPEGs but RAW for sure. Two versions back it worked fine and id so for many months. however, issues with Do Not Import Duplicates has been on ongoing issue with Aperture. for the first six months of use it never worked and then at somepoint it started working. I began relying on it and now it's out of use again. Strange.
Currently Being ModeratedAug 21, 2012 8:52 PM (in response to Jim Bridger)
I just did a test. In an old library, where I had imported the files a year or so ago, the 'do not import duplicates' fails, when i import - duplicates are imported. I created a brand new library and imported only 5 of the files. then i tried to import them again, and they did not show up, which is the desired outcome.
I think that some of the data in the files changes over time, (although all visible data seems identical) and so files imported in one year, are somehow different a year later, and Aperture does not recognize them as duplicates.
Currently Being ModeratedAug 21, 2012 9:27 PM (in response to Jim Bridger)
I have this issue sporadically. I think it's a bug that needs to be fixed. There's an article about this on ApertureExpert.
BTW, if you are renaming images on import, the Do Not Import Duplicates will not work. Never has in that case. I do not rename the masters and I still have the issue.
Currently Being ModeratedJan 5, 2013 2:25 PM (in response to Jim Bridger)
Im new here so forgive me if this has been answered.. I was having the same problem with Aperture importing duplicates while the "Do Not Import Duplicates" was checked.. I noticed that some of my photos stopped displaying file size in the metadata EXIF field. I deleted and updated previews. This takes a long time to process!! When its finished processing close Aperture and reopen. This seems to have solved the issue..MacBook Pro, Mac OS X (10.6.8), Aperture 3.2.4
Currently Being ModeratedJan 18, 2013 1:07 PM (in response to Jim Bridger)
My workflow had been plagued by the same problem and I had been brainstorming on this issue for a while. Finally, I have detected that this issue occurs when I manipulate the image files outside Aperture. In some cases Aperture will correctly detect the changes and update the information in its internal database to reflect these changes. But in some other cases (e.g. the image file size change) AP3 will not recognize the files as duplicates and list them in the import dialogue even when the "do not import duplicates" is checked.
I have deviced a workaround which involves updating one database table with the correct values and explained it in detail in my blog. This solved the problem for me. Hope it helps.