[ trunk ] R4814 Navigator not updating when adding/removing pages

The navigator window doesn't update when I add or remove pages. When I create a new score and force line breaks to get a second page, the nav window will still show only one page until I adjust the height of the nav window.

When this happens, the nav window blue box can be dragged left and right much too far, until I adjust the height of the nav window and everything is OK again.