Scrolling breaks draw2d

[28raining]

There seems to be a bug that if the page is scrolled at all Draw2D stops working. At least that is what I experienced.

To fix this I swapped;
this.setScrollArea(document.body);

For;
this.setScrollArea(window);

prompted by this; https://stackoverflow.com/questions/32277323/jquery-scrolltop-method-not-working

It took me a really long time to debug that! Hope it's helpful...
I think perhaps scrolling never worked? Or just in my setup...