I am still using Aperture 2. (please note that this is different in Aperture 3.) and I just realised that even though I always delete using the “Delete Master images and all versions” the files don't actually delete from my computer.
I import pictures directly from camera to aperture.
I store the images in aperture
I use Delet Master images and all versions
I empty the finder- trash can
— > and there is no change in how much space there is on my disk, witch brings me to believe that the files don't properly delete.