PDF export not working well with high res images as links? InDesign portfolio

When I try exporting doing the compression: automatic and 96 PDI I get blurred images and it loads very slowly, sometimes images even disapear to reveal the background? 

What am I doing wrong? Could it be layers? Links? The compression? Its only 5 pages, there are like 30 images though, not compressed before dragiging them into InDesign (so they are links?)