found a bug in IE8 with the demo page (http://www.i286.org/examples/index.html)
Code:
Highcharts.Chart.prototype.remove = function () {
/**
* Clear certain attributes from the element
* @param {Object} d
*/
function purge(d) {
var a = d.attributes, i, l, n;
if (a) {
l = a.length-1;
for (i = l; i >= 0; i -= 1) {
n = a[i].name;
//if (typeof d[n] !== ‘object’) {
if (n == 'coords') {
//d.parentNode.removeChild(d);
d[n] = '0,0,0,0';
} else if (typeof d[n] != 'object') {
d[n] = null; //<---------------------here... IE says "Could not get the align property"
}
}
}
a = d.childNodes;
if (a) {
l = a.length;
for (i = 0; i < l; i += 1) {
purge(d.childNodes[i]);
}
}
}
I used the build in debugger to inspect the objects and found that
the object d does have a property called align which is set to an empty string...
so very strange behaviour indeed...
PS highcharts looks great and well done you guys for integrating it with ext 
I've been using flot for a while but with ext3.x it's starting to give me problems...
so i look forward to using highcharts soon!! 
keep up the good work, i'll see if i can find out what's going on with IE...