Ok, I tried reverting back to 1.6.3 and 1.6.2, but to no avail either. I had made back ups prior to each upgrade and what I did to revert was to delete the contents of my current buddypress folder and upload previous versions. I cleaned the cache, but still no submenus.
Another weird behaviour I noticed was after removing my submenu from a Theme Location in Appearance/Menus, a menu/navbar would indeed appear, but it would be a complete listing of the pages of my sub-site, something I had never configured or set up to do.
