This is rather inconsequential in the bigger picture, but having discovered it by accident I thought I'd report it anyway.
I use a free utility called
http://classicshell.sourceforge.net/features.html which conveniently adds the old XP-style expanding Programs-menus to the Win7 start menu. (Well, ok, it replaces the whole of the start menu itself with a more configurable one, but you get the idea - more things running constantly in the background.)
As DF has the (endlessly useful) Middle-Mouse-Click on the title-bar to send that window to another monitor, it seems to interpret the small sub-windows from CS as "real" windows - even though they have no true title-bar (for once, the DF buttons don't "mysteriously" float or otherwise appear, as is proper).
However, if one happens to middle-click at the top of one of these child windows, it gets anomalously zipped off to the other LCD, as such:
...becomes...
Naturally the first port of call in DF is Compatibility settings, wherein one
unchecks "Allow middle-click window moving with this application" - except that doesn't work. For some reason it continues to happen. So, just for sport, one
unchecks all the compatibility options, "just in case". Nada.
What does work, however, is checking the "Pause Global Application Hooks" options. Except, as Classic Shell is always running in the background, that means DF's Application Hooks would be disabled all the time, which is impractical.
So, the simple question is, why doesn't
disallowing "middle-click window moving" seem to apply?
To underscore just how meaningless this issue is (asteroids hitting the earth, famines, and chocolate ice-cream being obviously more important issues), there is no reason during normal use of CS to ever middle-click on one of its menus. No reason at all.
But, humans being humans, now that I discovered it happens, it's like instinctively reaching for a cigarette when you know you've just quit. My mouse just can't resist it.
Like I said, dumb, but is does highlight a slight flaw in the compatibility routines...