Originally Said By: Eric Mittman
It may have to do with how you are editing the menu as I'm not able to get this result with a similar set of steps. I would suggest that you create a new menu and specify it to be a horizontal menu all along the way and when you save the preset include Horizontal in the title so you know to use that one for the horizontal applications. 
That appears to be it. I made a new menu and started horizontal. Then I could change it to vertical without a problem. It still seems to be a glitch. I should be able to create a menu with a separate default vertical and horizontal profiles. If I want to make a menu with some space between the menu and the fly-out menu, those settings have to be different between vertical and horizontal, but it does not appear to do that (or gives me no confidence that it is doing that). I should be able to pick a theme and switch between vertical and horizontal menus that both match the theme look and feel without adjustment.
Right now I made a vertical and horizontal version. I have not made many yet, so I might be missing something.
