OS: Suse 11.1
When a directory entry is manually deleted from the start menu using the KDE menu editor then a "Deleted" entry is stored in the file
If the directory is to be reinstalled using
xdg-desktop-menu install polfha-verzeichnis.directory <list of menu entries...>
then the directory entry does not appear in the start menu. It is was not before I had removed the "Deleted" entry from application-kmenuedit.menu that the reinstalled directory entry showed up in the start menu.
This is a kde/kmenuedit implementation detail, and I'm not sure if there's anything xdg-desktop-menu can (or should) do about it.