Acrobat/InDesign/Illustrator Help!

I want to show a client something in a .PDF file, I want to show him images, etc. they are all 72 resolution (web/screen resolution). When I put the .JPG file into Illustrator and Save it as a .PDF file, go "Full Screen" (even if its not full screen) the picture is all distorted/pixelated/out-of-focus, whatever you want to call it


Is there some way to solve it?

Thanks a bunch