help with UltimateParent in menù building

hi, I tryied to build a menu following theese instructions on "The (almost) Complete Guide to Creating Menus in MODx Using Wayfinder" http://modxcms.com/forums/index.php/topic,34176.0.html chapter 15: UltimateParent snippet and Wayfinder menu p.119.
I want a submenu showing only the current directory documents, but I get 1 step in the hierarchy too high.
The document tree is like:

• ...
• works(59)
  [list]
  [li]residential(79)
  [list]
  [li]House 01(82)
• House 02(88)
• House 03(87)
• ...

[/li]
[li]commercial(63)

• comm 01
• comm 02
• ...

[/li]
[/list][/li]
[/list]


Please see attached screenshots:

• screenshotManager.png shows the site tree (and the template code)
• screenshotMenu.png shows UltimateParent and the generated menu’, in the file "House 3".

As you can see the UltimateParent results Works(59), while I was expecting residential(79).
Do I miss something? Any help is appreciated.
Thank you.