Jim,
Did these corrupted files display previously without any problems? If they are previously processed then it could be a couple of problems, software - unlikely, or a hdd beginning to fail - more likely.
If it is as you say files which have been printed via Lightroom, try copying some other uncorrupted files and print the copies, see if they fail too. If this is the problem then maybe re-install Lightroom.
Just my thoughts.