Error in footer when logged in

After migrating wordpress to a new server, I now have an error in the footer of my wordpress website that is only visible when I’m logged in. Here is the error:

<!-- X --><br />
<b>Fatal error</b>:  Call to a member function get_queried_object() on a non-object in <b>/home/username/mywebsite.com/wp-includes/admin-bar.php</b> on line <b>440</b><br />

Here is the referenced line causing the error:
http://core.trac.wordpress.org/browser/branches/3.3/wp-includes/admin-bar.php#L440

$current_object = $wp_the_query->get_queried_object();

Anyone have any ideas how to troubleshoot this one?

Many thanks in advance.