I've been trying to make Squeak work better on my touch-screen (pen) based WinCE device.
A particularly annoying problem is that it's almost impossible to get out of window/pane resizing mode once you get in.
The reason is that no mouse events occur between mouse up and mouse down.
I fixed the pane resizing problems in MVC with the enclosed method change.
But the Morphic resizing problem is trickier.
The NewHandleMorph that is created to do the resizing does, in fact, delete itself when the mouse (pen) up occurs.
However, the SystemWindow then notices that the mouse is still over the frame border and creates another NewHandleMorph.
Now, since the pen is up and there aren't any mouse events while the pen is up, the NewHandleMorph stays around waiting for a click. When you finally put the pen down, it starts tracking the mouse movements. The whole process repeats.
The only way you can get out of this mode is to move the pen into another window and tap inside it.
The same thing happens, I think, with window border resizing (but I'm using the WindowFrame stuff so I can't tell easily).