Sorry, I always do the documentation last, but I should have said something about this...
the red rectangle is the same size as the graph on the parent window. If you place GUI objects inside it they show up on the parent... WITHOUT STETCHING. I think you'll agree it's much much better than the old way...
To change the size/location of the red rectangle, get out the properties dialog for the canvas (it's now the same dialog from the parent as from the canvas) and set "size" and "margin" parameters.
well, this makes gops much more usable ... still, this rectangle shouldn't show up, if i place an array on a canvas and gop is switched off ;-)
t