 <p>I found few issues on a first look, you should change the :</p> <pre><code>$dom.bind('mousedown.auto_dropdown_box_ul' </code></pre> <p>to:</p> <pre><code>$dom.unbind('mousedown.auto_dropdown_box_ul').bind('mousedown.auto_dropdown_box_ul' </code></pre> <p>To prevent multiple events binding to the dom node, you can also use .one event handling of jQuery. In the same event handling you should also put:</p> <pre><code>console.log('bind mousedown'); e.preventDefault(); return false; </code></pre> <p>To be sure event is not firing.</p> <p>Hope this helps (I'm not having IE8 for a long time now)</p>