I don't know if I'm doing something wrong, but it seems that if I have a document with multiple nested heading levels displayed in "outline" mode, then word is very quick to forget which headings are "open" or "closed". For example, if I close all the level 2 headings, then close their parent level one heading, then when I re-open the level one heading, all the level 2 headings have become opened again. Similarly, whatever state of open and closed headings I have when I save the document. When it comes to re-loading it, all the headings are now open.
Is there some option to instruct word to leave things open/closed unless instructed otherwise?