In my drag/drop test, I have a "source" dialog and two "target" dialogs. The two targets are two instances of the same dialog class.
 
However, the mapWindowPoints() does not map correctly when I move the mouse over the second target dialog (or sometimes over the first) -
the mapping is to a place well away from the target dialog (sometimes above, sometimes below). Hence the cursor does not get set correctly (it stays as NoEntry until I get to the place where it thinks it's mapping to the dialog).
 
On the mouse move event, I do the following (aside from other things of course):
 
      say "DragManager-moving-01a: hwnd/mousePos =" hwnd "/" mousePos
      sourceDlg~mapWindowPoints(hwnd, mousePos)
      say "DragManager-moving-01b: hwnd/mousePos =" hwnd "/" mousePos
 
When I'm over the target dialog (but the mouse is still "no-entry"), the command prompt shows, for example:
 
DragManager-moving-01a: hwnd/mousePos = 0x003B07D8 / a Point (-205, 192)
DragManager-moving-01b: hwnd/mousePos = 0x003B07D8 / a Point (-205, -133)
 
Is this my code, or could there be a problem with mapWindowPoints()?
 
Many thanks,
Oliver