Aperture 1.5: External editor not bringing image back into Aperture?

I am running Aperture 1.5 and have Noise Ninja installed as my external editor. I can successfully send an image from my Aperture library to NN and edit it there, but when I save the image, it is not brought back into Aperture. Further, if I try to send another image from Aperture to NN while NN is open, a new TIFF version is created in Aperture, but nothing opens up in NN.
I've been using Aperture and NN for about a year, and it has always acted like this, so I've basically given up on trying to use the External Editing feature in Aperture, but after some research it seemed like this shouldn't be as difficult as it has been for me.
Has anyone else had a problem like this and been able to resolve it? And does it matter that my files are referenced, and not stored in the Aperture library?
Thanks all


Did you ever find a solution? I'm having the same problem with Photoshop files not saving back into Aperture. I haven't been able to figure it out.