I may have narrowed the issue. It only happens when I print from RAW files. Printing from jpg files seems to be OK. I did an online chat with Adobe and seem to have determined that my NEF RAW files imported into LR5 from my card reader were corrupt. When I copied the NEF files off of the card onto my hard drive, then imported the files into LR, then printed them, they were fine. So the issue seems to be that I cannot/should not import from the card directly into LR. Who knew?
I will experiment further to see if that is truly the case, but all signs point to that bug being the issue.