> Okay.  I would have thought this kind of thing was handled in
> handleMouseDown: , but you're right.  I don't know why 
> handleMouseDown: *doesn't* do these things.  

Legacy. There are plenty of places where it is *expected* that the
#mouseDown handler blocks the default semantics. Believe, I did think of it.
I just couldn't make it work.

Cheers,
  - Andreas