That's new.. I tried that when I built the my minimap plugin for the EQ2Map project. Me and zonx played around and discussed it back then.. We found that, you used to have to actually move the dummy window with the mouse for it to save location.
http://www.eq2interface.com/forums/s...ead.php?t=2839
Great find, Glad they updated the way the location saving works. Now I want to come back and play around with UI's just to see what else they've fixed and added.
edit: Something else I was thinking back then.
If it saves whether frames and titlebars are visible on the dummy dummy window you should be able to set it up to remember if the window was docked the last time you logged out also