If the "Submenu delay" second is set to zero, the menu item under the mouse will always be selected immediately. The menu then behaves as if you moved the mouse over the menu with mouse button 1 held down all the time.
However, if the submenu delay setting is raised, &xwp; will delay the menu item selection for the time which you specify here. This is useful to avoid lots of unnecessary screen repaints. Also, some submenus may take quite a while to compose (such as &xwp;'s folder content menus).
If "Conditional cascade sensitivity" is enabled, &xwp; will give special treatment to submenus with the "conditional cascade" style (i.e. those submenus with the button in them). Such submenus will then only open if the mouse is moved over the button and ignored otherwise. This is more like the NPS WPS behavior, if you prefer that.
If the submenu delay above has been enabled, the "Immediate hilite" box gets
activated also. This will always high-lite the menu item under the mouse immediately
without actually selecting it. That is, the menu item under the mouse will always be
painted in hilite color, but if it's a submenu, the submenu will only open after the
"submenu delay". This is pretty close to the Windows 95 behavior.