Didn't seem to work for me: when I tried to move the nodes the whole diagram shifted rigidly.
This is by design :) When you click node, diagram should be positioned to the center of the screen. When you move it with mouse, it should move as expected.
Oh. The site says you can "arrange" the diagram. I don't interpret "arrange" to mean shift position without changing the ... arrangement.
You are right, my bad. I commited a bug in documentation :) Fixed now.