very good. thanks for the help. yes, i make a habit of locking viewports, but this setting was proving to be annoying in spite of that. any viewport unlocked for whatever reason during drafting goes around re-scaling itself... the insubordinate behavior of the unlocked viewports was affecting viewport morale for the whole drawing.
Slant, one thing to think about. As you said you had only one drawing that was doing this. This setting got changed somehow, either manually by someone or a lisp program (third party program). Something to look into so it doesn't happen again because as you and I know settings don't change themselves. You didn't state if you were the only one who had worked on the drawing.
yeah, it's an old drawing being updated to a new design. plenty of users have had access over the years. somebody did somethin, but trying to track it down would be futile. just needed to know some random setting for a fluke.