Let me thank everyone one more time. I was successful in copying file from the 840 filer (6.1.1R2) to the NearStore (6.2.1) without upgrading the 840. By running this command from the NearStore it worked:

NEARSTORE> ndmpcopy -sa root:rootpassword -da root:rootpassword -st text -dt text 840:/vol/vol0/Test NearStore:/vol/vol0/test

Thanks to everyone's input I realized I needed to add the -st option and, after awhile the obvious was revealed---the path needs is case sensitive. Once I had these two elements in place everything worked. So thanks again for everyone's help. I also now have fresh, new root passwords for all of my filers!!!