I am not sure whether it worked before. But after I changed from stable to dev to fix the sqlstate#### bug, I cannot refer to the URI of a reference anymore.

$field_lieder is a reference to a node type. I used this code in my template to get the URI of the refered node:

foreach ($field_lieder as $lied) {
    print '<li>';
    print '<a href="' . url($lied['node']->uri['path']) . '" title="' . $lied['node']->title . '">' . $lied['node']->title . '</a>';
    print '</li>';
  }

Now I get the following error message:

Notice: Undefined property: stdClass::$uri in include() (Zeile 102 von /var/www/drupal/sites/all/themes/mytheme/templates/node--alben.tpl.php).

How can I fix this?