Vaadin charts v1.1.1 error on IE8


in my application everything works fine with Firefox 8.0.1.

However with Internet Explorer 8, which is the browser our customer uses, the chart doesn’t show up.

With the IE web developer tools I can see the following problem:

We get an error in the following javascript function:

 * Extend an object with the members of another
 * @param {Object} a The object to be extended
 * @param {Object} b The object to add to the first one
function extend(a, b) {
	var n;
	if (!a) {
		a = {};
	for (n in b) {
 = b[n]
	return a;