jQuery dates not sort sorting properly and li element jumps when button is pressed
<p>I've managed to figure out how to sort my dates in jQuery but it came to my attention that certain dates are not being sorted correctly and there is an little jump when one of the buttons are pressed. How can I resolve this? I've posted up my code at <a href="http://jsfiddle.net/Erah9/1/" rel="nofollow">http://jsfiddle.net/Erah9/1/</a>. Here is my code so far:</p>

<p><strong>HTML</strong></p>

<pre><code>&lt;div style="padding-top: 20px;"&gt;
&lt;input class="btn" type="button" value="Oldest First" id="sortAsc"/&gt;
&lt;input class="btn" type="button" value="Newest First" id="sortDesc"/&gt;
&lt;/div&gt;

&lt;div id="wrapper" style="padding-top: 20px"&gt;
        &lt;ul&gt;
        &lt;li class='item'&gt;&lt;div class='activity_date'&gt;01/10/2012&lt;/div&gt;
        &lt;div class='activity_box'&gt;
        &lt;div class='activity_text' id='act'&gt;Allocated request&lt;/div&gt;
        &lt;/div&gt;&lt;/li&gt;&lt;li class='item'&gt;&lt;div class='activity_date'&gt;03/10/2012&lt;/div&gt;
        &lt;div class='activity_box'&gt;
        &lt;div class='activity_text' id='act'&gt;Failed request&lt;/div&gt;
        &lt;/div&gt;&lt;/li&gt;&lt;li class='item'&gt;&lt;div class='activity_date'&gt;08/10/2012&lt;/div&gt;

        &lt;!---------------- 
        SEE JS FIDDLE FOR MORE OF THIS
        -----------------&gt;        

        &lt;/li&gt;          
        &lt;/ul&gt;
&lt;/div&gt;
</code></pre>

<p><strong>JS</strong></p>

<pre><code>   $(function(){ 
    var itemsArray = $('li.item');
    itemsArray.sort(function(a,b){
        var aTime = new Date($(a).find('.activity_date').text()).getTime();
        var bTime = new Date($(b).find('.activity_date').text()).getTime();
        return aTime - bTime;
    });

    $('#sortAsc').click(function(){
        $("#wrapper").empty();
        $(itemsArray).each(function(){
            $("#wrapper").prepend($(this));
        });
    });

    $('#sortDesc').click(function(){
        $("#wrapper").empty();
        $(itemsArray).each(function(){
            $("#wrapper").append($(this));
        });
    });
    });
</code></pre>

<p>Thank you so much! in advance
    ​</p>
