Cant add images after Windows 7 Upgrade

Has anyone experienced this before…

Using the latest Wp v.3.2.1 on website https://www.pintofmilk.net
Website worked fine until abt 6 wks ago when i couldn’t upload images from the ‘Add an image’ icon on WP Dashboard using Windows 7 and IE9 on my laptop. I can do it from Firefox but had to disable firefox. I can add images from other laptops which is also Windows 7 and IE9.

Thought it was a popup blocker, checked everything, it’s not that.
Tried debugging and kept getting the error msg (see the problem code line in bold below)Should I be worried that the word ‘Hack’ is in the code? Can anyone help?

Jscript Debugger – Breaking on Jscript runtime error – Invalid calling object’

// set up DOM events for Google Chrome & Mozilla Firefox
if (isMozillaFirefox || isGoogleChrome || isAppleSafari)
{
doc.addEventListener(“DOMNodeInserted”, onDOMNodeInserted, false);
doc.addEventListener(“DOMNodeInsertedIntoDocument”, onDOMNodeInsertedIntoDocument, false);
}
// HACK : override appendChild, replaceChild, insertBefore for IE, since it doesn’t support DOM events
if (isInternetExplorer)
{
var appendChildOriginal = doc.body.appendChild;
doc.body.appendChild = function(element)
{
appendChildOriginal(element);
var tag = element.tagName.toLowerCase();

if (“video” == tag)
{
ProcessVideoElement(element);
}
}