I use Connectors  a lot.  Recently I began to have an unusual problem.  
When I select something (a morph) small handles appear at the border, 
but when the morph (or the menu) is displaced or deleted all the lines 
and the littles boxes compositing the border stay in place.....
These happens to be  'NCHighlightMorph'

what created that and how to get rid of them ?

Raymond