No, these are simply .pdfs that I have dowloaded and opened up in preview. Some are worse than others, but nearly all are affected. When I create them they seem to be fine.
Try downloading Adobe Reader then, and see if the same problem happens. If you get the same problems, then there's something wrong with the particular PDFs that you're viewing.
If you can post a link to the original source where you downloaded those pdf's we can see if the problems shows up on our computers, which would mean the source files are at fault.
This is just the most recent file I've had an issue with. There have been many others which were much worse. The mangled portions seemed to be in the headers, or anything bold. And yeah, it prints all jacked up.
OK, I've opened it up in Acrobat Pro and the main problem with this one is that a number of Windows Truetype fonts are not embedded within the document, which means that if you don't have the fonts on your machine, parts of it won't display properly.