Why does IE give unexpected errors when setting innerHTML

// removing the scripts to avoid any 'Permission Denied' errors in IE
var cleaned = html.replace(/<script(.|s)*?/script>/g, "");

// IE is stricter on malformed HTML injecting direct into DOM. By injecting into
// an element that's not yet part of DOM it's more lenient and will clean it up.
if (jQuery.browser.msie)
{
    var tempElement = document.createElement("DIV");
    tempElement.innerHTML = cleaned;
    cleaned = tempElement.innerHTML;
    tempElement = null;
}
// now 'cleaned' is ready to use...

replaceInReadOnly(document.getElementById("links"), "<a href>........etc</a>");

function replaceInReadOnly(element, content){
    var newNode = document.createElement();
    newNode.innerHTML = content;
    var oldNode = element.firstChild;
    var output = element.replaceChild(newNode, oldNode);
}