What file type are the graphics?
How does it look when you turn on high quality display?
How does it look when you export it to PDF/X-4?
InDesign file. The lines are vector art within InDesign (not linked) and the background is a 'Pasted Graphic'.
And that was my initial thought too, but the problem still persists with high quality display on and even when exported to a PDF. When I copy/paste the background into Photoshop it shows the same pixel problem.