This issue was originally filed by xavier.haina...@gmail.com

What steps will reproduce the problem?
import 'dart:html';
main() {
  CanvasElement canvas = querySelector('canvas');
  ImageElement img = new ImageElement(src: 'dice.png');
  img.onLoad.first.then((_){
    canvas.context2D.drawImageScaledFromSource(img, 0, 0, 120, 120, 0, 0, 60, 60);
  });
}

What is the expected output? What do you see instead?
In chrome and Dartium: it works as expected
In Firefox: "Index or size is negative or greater than the allowed amount"
Safari: there is no error but it doesn't draw anything
InternetExplorer: "Uncaught Error: IndexSizeError"

What version of the product are you using? On what operating system?
Editor: 1.2.0.dev_05_11 (2014-02-19)

Please provide any additional information below.