Dropdown primary navigation menu not working

Question

I have installed a theme on WordPress added pages, created a custom menu called Primary Nav. I have then assigned this as my Primary Menu. I have child pages and the menu looks like this.

I have looked at the WordPress resources to find a solution but it seems as though I have followed the instructions on creating drop-down menus.

However when I go to the previewDNS site the drop down doesn't work.

The code is below, if another area is required please let me know where on the source page I will find it and I will add here.

    <div class="ddsmoothmenu"><ul id="menu-primary-nav" class="menu"><li id="menu-item-125" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-125"><a href="http://hutchisonhaines.co.uk.previewdns.com/?page_id=27">About</a></li>
<li id="menu-item-117" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-117"><a href="http://hutchisonhaines.co.uk.previewdns.com/?page_id=47">Portfolio</a></li>
<li id="menu-item-119" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-119"><a href="http://hutchisonhaines.co.uk.previewdns.com/?page_id=41">Packages</a>
<ul class="sub-menu">
    <li id="menu-item-120" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-120"><a href="http://hutchisonhaines.co.uk.previewdns.com/?page_id=103">Photography Prices</a></li>
    <li id="menu-item-123" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-123"><a href="http://hutchisonhaines.co.uk.previewdns.com/?page_id=97">Wedding Albums</a></li>
    <li id="menu-item-122" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-122"><a href="http://hutchisonhaines.co.uk.previewdns.com/?page_id=99">Signature Frames</a></li>

    <li id="menu-item-121" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-121"><a href="http://hutchisonhaines.co.uk.previewdns.com/?page_id=101">Wedding Stationery</a></li>
</ul>
</li>
<li id="menu-item-124" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-124"><a href="http://hutchisonhaines.co.uk.previewdns.com/?page_id=31">Blog</a></li>
<li id="menu-item-118" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-118"><a href="http://hutchisonhaines.co.uk.previewdns.com/?page_id=44">FAQ&#8217;s</a></li>
<li id="menu-item-116" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-116"><a href="http://hutchisonhaines.co.uk.previewdns.com/?page_id=72">Contact</a></li>
</ul></div>