Duplicates created in error

Question

Not often, but on occaison, Aperture 3 creates duplicates when moving photos from one project to another (eg,: moving a freshly edited batch of pics from "Untitled 1" to an on-going project folder). To illustrate - I drag all of the pics from Untitled project into "Project Z". All of the photos successfully make the move and a small number of them are copied but the originals remain behind in "Untitled 1". Any attempt to drag those left behind stay put but another set of copies are created and reside in the folder they were dragged into. I have found that deleting all of the dupicates, regardless of which project folder they're in, does successfully delete them.
Have tried rebuilding Aperture database and repairing Aperture's permissions to no avail.

Answer 1

I think we'll need some clarification in order to helpfully proceed.  You start off talking about moving from Project to Project, but then you shift and begin to refer to the destination container as a folder.
Aperture Folders hold other containers; they do not hold Images which are not in containers.
The target of your drag-and-drop will determine the action performed.
Let us know more exactly what you are doing, what the results are, and how they differ from your expectations, and someone is sure to jump in with help.
If you wish to move all of the Images in a Project to another Project, the easiest way to do it is to go to Projects View and drag-and-drop the Project-to-be-emptied onto the Project-to-be-filled.  Aperture will ask you to confirm that you wish to merge the Projects, merge them, and delete the Project-to-be-emptied.  No duplicate Images are created.