I'm not sure, I remember I modified it based on the one from here
and studying the white paper here
If you find a way to modify the mojoPortal.MenuAdapter to facilitate StaticDisplayLevels let me know and I'm glad to make the change. If not I'll try to look into it myself when I have a chance. I would think some additional css classes could be setup for this and then assigned in the adapter beased on the attribute.
Its possible to bypass the adapter as well by declaring a new class that inherits from ASP.NET menu. I did this during an experiment trying to decide if I wanted to use the Menu control for the MyPage feature. I ended up not using it but you can see in Web/Controls/PostBackMenu.cs (AutoPostBack also doesn't work with the adapter)