I hadn't noticed this note, but an observant site reader (thank you) pointed it out to me. It explains something I saw when I pulled up some images in Aperture 3: the new version of Aperture is processing exposure a bit differently for different ISO values than the previous one. Other Apple Knowledge Base notes for Aperture 3 with references to Nikon include Mac OS-X 10.5 not rotating images correctly, pixel dimensions being different, and the fact that you'll be switched to 32-bit mode when you use older 32-bit plug-ins such as those from Nik. Aperture 3 was indeed a major update. Not only did the feature set and observable performance change, but so too did some of the plumbing underneath.