Thanks very much to Klaus and Protected for trying to help me here.
okay, but your xml is not easy to understand...

to what have you set the "parent" attribute for the image and to what for the hotspots?
I know it's hard to read, because you don't see the comments in the editor. If you wish, I can send you the original xml files as a private message, but of course you can also just pluck them off the server.
The floorplan image (top left) has no parent set, while the icons on it have plugin[floorplan] as parent.
Also the housemap (white surface bottom left) has no parent, and the images on it have plugin[housemap] as parent.
The names of the icon plugins, made with addplugin(), start with "plugin_".
The hotspots (magnifying glass) have no parent set. They are created with addhotspot and their names start with "hotspot_".
I can't find addhotspot/addplugin in your xml files, can you please tell me where they are? You have a lot of stuff there spread across at least 3 files so I may have missed it.
krpano.xml contains all the code (will be used to display all kinds of estates). Floors.xml contains the data structure for this particular estate.
The plugins and hotspots are created in <action name="create_spot">
<!--
Creates an image hotspot or image plugin
%1 = object instance that contains general data of all floors|panos
%2 = object instance that contains general data of this floor|pano
%3 = object instance that contains specific data for this spot
%4 = object instance that contains specific data for this visual layer of this spot
%5 = core name of plugin|hotspot to be created (without "plugin[]" or "hotspot[]" itself)
%6 = type: "plugin"|"hotspot"
%7 = offset to parent's zorder
-->
To find addhotspot() or addplugin() there, look for add%6 instead.
I know it's very overwhelming at first, I'm sorry about that. It's also not my latest code, yesterday I figured I can use images with multiple icons in it, and then crop the desired part, which divides my number of plugins needed by 3.
But I thought the real-time information as can be obtained from the xml editor is more useful, because there you can inspect the objects as they are at the very moment they are misbehaving...