Some PDFs created by MS Word 2007's Save-as-PDF feature (on Windows) don't display correctly on Mac OS / iOS Some PDFs created by MS Word 2007's Save as PDF feature (on Windows) don't display correctly on Mac OS using the built-in PDF handling. They display correctly using Acrobat, Photoshop, Inkscape, or probably any other app that uses it's own PDF rendering, rather than the native quartz rendering. This problem is also visible when viewing the PDFs on an iPhone / iPad.

This PDF displays as 
http://www.schimmelpenninck.net/pix/blurred_pdf.png

There is a discussion here, but it doesn't have an useful answer.

Is there anything that can be done in Office 2007 on Windows to make it create PDFs that don't have this problem?
There isn't anything you do to Word to improve its PDF output. The best way to guarantee solid cross-platform PDFs is to get Adobe Acrobat (the full version, not Reader) and Distiller and make PDFs through those applications. Unless something has changed since the last time I did this on Windows, you'll output to Postscript through the Print window and create the PDF with Distiller, but you need Acrobat to get the drivers and converters. PDF is an open ISO standard, but Adobe's products are still the best way to go here.