Degraded quality of photo printing book in Aperture 3

Hi,

I've isolated an issue in the print book function of Aperture 3 that drove me crazy in the last ten days:

I've created a custom size book to deliver to a local print service via "save as pdf" function, but something gone wrong because the quality of the pdf isn't good as the original photos.

After days of trials I've found where the problem rises up, so I'll try to explain step by step below:

I've identified one critical photos that well shows the problem and I've "printed to pdf" from the normal print photo function of Aperture and the results was correct:

So I've created a book and put that photo in a page and I've "print to pdf" the book. The results was degraded like you can see below (look at the dark areas that have lost every details):

I've done the same operation in iPhoto, the "non Pro" minor App, and in a paradoxical way the iPhoto results PDF was perfect!

I've also noticed that the preview image of the print dialog box of Aperture shows the defect unlike the dialog box of iPhoto:

Aperture:

iPhoto:

So finally seems that something in the print engine of books in Aperture is broken and ruins the photos "before" are printed, and apparently no setting seems to help.

I've done this tials on a MacPro Lion 10.7.5 ad Aperture 3.4.3, MacBook Pro Lion 10.7.5 ad Aperture 3.4.3 and MacPro Snow Leopard with aperture 3.1 and 3.2 always with the same results.

you can download the generated PDF here:

pdf Aperture Photo:

http://temp.paolorossi.me/ApertureImagePrint.pdf

pdf Aperture book:

http://temp.paolorossi.me/ApertureBookPrint.pdf

pdf iPhoto book:

http://temp.paolorossi.me/iPhotoBook.pdf