[Therion] Multiple layers of overlayed maps

[Bill Gee]

Hello everyone - 

Therion 5.3 (stable) running on Fedora 14 ...

I am working on a cave which has a very complex maze area.  Basically the maze 
area can be divided into either 3 or 4 layers (depending on how you draw it) 
which are stacked on top of each other like a cake.  I want to produce a map 
where the lowest part of the maze displays with the rest of the main passage, 
and each higher layer of the maze is offset from the layer below it

So far I have figured out how to get one layer to offset and have its outline 
(the "preview", I think) display over the main passage.  Now I want to take 
the next layer and have its outline display over the layer below.  Here is 
what I think should happen in the .TH file:

===============
map MainCaveMap -title "Elkton Cave - Plan View" -projection plan
  MainPassage at ElktonCave
  UpperMaze at ElktonCave [200 30 ft] above
  UpperMaze2 at ElktonCave [200 -100 ft] above
endmap

map MainPassage -title "Elkton Cave - Plan View" -projection plan
  (many scraps, names removed for clarity)
endmap

map UpperMaze -title "Upper maze area" -projection plan
  MazeA
  MazeB
  MazeA2
  preview above MainPassage
endmap

map UpperMaze2 -title "More upper maze" -projection plan
  MazeC
  MazeD
  preview above UpperMaze
endmap
================

When I compile the map, it draws the offset maps correctly,  However, ALL of 
the outlines are over the MainPassage map.  I don't want that ...  I want an 
outline of UpperMaze over MainPassage, then I want an outline of UpperMaze2 
over UpperMaze.  I thought that is what would happen with the "preview" 
directive.

Does anyone have suggestion?

Thanks - Bill Gee