Overlapping transparencies in Illustrator

I am working in illustrator to create a magazine ad. I have inserted a .psd file that does NOT have a background. But for some reason, it is creating transparencies in other parts of the ad where the images overlap. It only shows up when I print though (does not show up in the .ai file or the .pdf). Does anyone have any suggestions on how to get rid of this transparency caused by overlapping images?