I have several times experienced that morphs disappear when a drag and
drop fails.
I think it's due to rule 3 in this method:

Morph>>rejectDropMorphEvent: evt
	"The receiver has been rejected, and must be put back somewhere.  There
are three cases:
	(1)  It remembers its former owner and position, and goes right back there
	(2)  It remembers its former position only, in which case it was torn
off from a parts bin, and the UI is that it floats back to its donor
position and then vanishes.
	(3)  Neither former owner nor position is remembered, in which case it
is whisked to the Trash"

What would be the best way to make sure the morph does not disappear 
if a drop fail ?

Karl