The obscurity of MenuBarItemSubmenu and its lack of document have seemed to make Spry Framework for Ajax fall short of being a full flagged, functional and well rounded, sustainable system for Dreamweaver.
This statement is nothing short of the truth and you are not the only one that has complained.
Having said that, once you are familiar with how the menubar works, you'll fall in love with its simplicity and ease of use. This can be said for the whole of the Spry framework, the Spry team have done a good job, but have not been allowed to finish off their good work. Much is the pity.
Thanks for your reply. I've used Dreamweaver since 2000 (was Macromedia Dreamweaver), so I have a natural attachment with the software. During the time, we purchased third party utilities to work with Dreamweaver, such as interactive form. Do you know any plugins or app that create great looking menus?