What's really strange is that this is not happening to all the files, just most of them. As the files are entered into MC17, most of the tag information is being modified on every record, i.e. title, artist name, album name and year.
I am using the standard setup for MC17. The changes are not doing any harm to the playlists I created in Nero Burning ROM 10 but still it is confusing.
With regard to tags, I though that when I modified the information such as adding a title to my "Track 1"'s that it would show up in my file management software but this doesn't happen so I just don't understand what's causing my files to be modified.