🚀 go-pugleaf

I'm relatively new to Framemaker and received a helpful answer from this group to my last problem, so I'm hoping that someone here can help me with a new problem. I am using FM 5.56. Most of the text in the book I'm working on is fully justified. When I generate PDF files from my FM files, the justified lines in places are not really justified on the right--e.g., the last character of a line will hang out into the margin, or succeeding hyphens at the ends of lines will clearly not be aligned. If I hold a straightedge to the text, it is clear that the text alignment is not straight. (In addition, in some attempts to generate PDF files, individual characters and whole words "drop out" in the PDF files--there is just a blank space where they should be, as if they turned white.) I had these problems a couple of years ago when working on another book, and Adobe support finally dropped my case as unsolvable and I was left with the problem (the printer agreed to accept my FM files and generate the postscript files on their end). Maybe I'm nuts, but a friend convinced me that that must have been a fluke, so I used FM to put this book together that I'm working on now. Some things I've tried: changing fonts; generating PDF by "save as" and by printing to file; doing a hard reboot of my computer. Has anyone else ever had similar problems, and if so, how did you resolve them? Thanks in advance! 
Rosemary