please send us url to page where you have vertical menu as we really have no idea how you did it.
About menus, it is possible of course to create unlimited menus. In Appearance > Menus section you need to create 2nd menu and then, when you create/edit page in "Page options" section you have "Custom Menu" option. If you didn`t choose any, then default one shows, but if you select, then selected menu will show only.
Also in Appearance > Menus section you should choose which one is Main menu.
Comments
please send us url to page where you have vertical menu as we really have no idea how you did it.
About menus, it is possible of course to create unlimited menus. In Appearance > Menus section you need to create 2nd menu and then, when you create/edit page in "Page options" section you have "Custom Menu" option. If you didn`t choose any, then default one shows, but if you select, then selected menu will show only.
Also in Appearance > Menus section you should choose which one is Main menu.
More info about custom menus you can read on http://forum.muffingroup.com/betheme/discussion/3/how-to-create-own-menus