Here's a mad problem.
When I print a PDF from OS X's Preview app that has been created from InDesign CS6, the output (Text and lines) appears noticably "dotty". Even straight lines have, under a loupe, visible dots along the edge. When printing from ID directly or Acrobat, I get no such dots, only smooth lines and curves.
However:
Printing directly from InDesign: No trouble.
Printing PostScript from ID and Distilling to a PDF: Problem occurs when printing from Preview.
Other content from other apps, using the same Distiller settings: No trouble.
Some older PDFs of similar content created in earlier versions of CS (CS3): No trouble.
Combined PDF of pages from ID CS6 and other apps: only trouble on the ID Cs6 pages.
Printing from Acrobat: No trouble.
In short, it's not the printer settings, as a combined PDF of pages from multiple apps will only display the problem on the pages that came from ID.
My printer is an HP 5200 DTN.
Answers other than "don't use Preview" welcome. 
I'm presuming Preview may well be at fault, but as InDesign has much more configurable options, I'm looking to adjust the output from there.
Any thoughts, or anyone else notice this? Thanks.