Aperture 2 projects

In my Pictures folder in my hard drive, i have everything organized the way i like it. Now i created projects in Aperture 2, and imported pictures from those folders i previously have. But when i go into Finder to my Pictures, i see duplicates of those folders in there. Then when i delete those duplicates, Aperture does show them, but it has a little warning symbol on it. Why is Aperture doing this?

Did you import them as referenced or managed?

Sounds like you imported them as managed and have told Aperture to use that drive for your library.

When Aperture manages your photos it will copy them into your library. If these are files already on your hard drive then you'll get duplicate images. If you then delete these duplicates Aperture will still have the thumbnails and intermediate images it created of the photos but won't have the original and will alert you to the fact with a warning symbol.

Try importing them as referenced files.