The last point is a good one. The way all Apple products (computers, iPhones, iPads) handle PDFs is really bad. Sometimes the Apple PDF reader refuses to draw the pages correctly, and a lot of the time if you print from the Apple-developed PDF viewer, your document won’t print exactly to scale. (I can’t tell you how many emails I’ve answered from people who are printing from a Mac and get a test square that’s 7/8 inch instead of an exact 1 inch!)
For that reason we always recommend viewing and printing our PDFs with Adobe Reader.
Trust me. It’s a near 100% certainty that if you have problems viewing or printing a PDF that you’ve downloaded it’s caused by something with your computer or printer, not with the file itself.