Problem solved. It turns out to be easy to get the new version of
Adobe Acrobat to display the Hyperbook properly. First, to get popups
to appear as popups rather than in a new tab, uncheck this option:
Edit > Preferences > General >
Open documents as new tabs in the same window (requires restart)
Second, to get rid of the annoying menu that takes up about the
right-hand third of the screen, uncheck this option
Edit > Preferences > Documents >
Open tools pane for each document
Leslie