I have a lengthy document in Word 2010 which makes copious use of standard header styles. These display hierarchically (and very usefully!) in the navigation pane. But the list of these sections and subsections in the navigation pane is somewhat lengthy, with all nodes being expanded by default. I am now working near the end of the document so every time I open the document I contract the first so many header 1 nodes to compress the list to fit on one screen. I then have direct access to the later sections while still letting me access the earlier sections if needed.

The problem is that as soon as I close the document all the customization I did in the navigation pane is lost. Is there any option or setting somewhere that will retain the expanded or contracted state of nodes in the navigation pane?