Double post FTW!! 
For anyone affected by the new Chrome Update (v36) which breaks some AJAX Toolkit features, create a file in your Javascript folder called Chromev36Fix.js, open it and add the following lines of code:
$(document).ready(function () {
if (Sys.Extended && Sys.Extended.UI && Sys.Extended.UI.HtmlEditorExtenderBehavior && Sys.Extended.UI.HtmlEditorExtenderBehavior.prototype && Sys.Extended.UI.HtmlEditorExtenderBehavior.prototype._editableDiv_submit) {
Sys.Extended.UI.HtmlEditorExtenderBehavior.prototype._editableDiv_submit = function () {
//html encode
var char = 3;
var sel = null;
setTimeout(function () {
if (this._editableDiv != null)
this._editableDiv.focus();
}, 0);
if (Sys.Browser.agent != Sys.Browser.Firefox) {
if (document.selection) {
sel = document.selection.createRange();
sel.moveStart('character', char);
sel.select();
}
else {
if (this._editableDiv.firstChild != null && this._editableDiv.firstChild != undefined) {
sel = window.getSelection();
sel.collapse(this._editableDiv.firstChild, char);
}
}
}
//Encode html tags
this._textbox._element.value = this._encodeHtml();
}
}
});
You will then need to add the following lines of code to the bottom of your Template.master page:
<script type="text/javascript" src="JavaScript/Chromev36Fix.js"></script>
You will also need to add the following lines to the bottom of your Skins/Admin/Template.master page after the </form>
tag:
<!-- Load up javascript -->
<script type="text/javascript" src="../JavaScript/k26000/jquery.js"></script>
<script type="text/javascript" src="../JavaScript/Chromev36Fix.js"></script>