Form states expanded or collapsed not working I cannot get this to work. Visible/Invisible works for me but this doesn't. Have I misunderstood anything?

    $form['items']['delivery_address'] = array(
    '#type' =&gt; 'fieldset',
    '#title' =&gt; '',
    '#collapsed' =&gt; true,
    '#collapsible' =&gt; true,
    '#states' =&gt; array(
        'expanded' =&gt; array(
            ':input[name="add_address"]' =&gt; array('checked' =&gt; false),
            ':input[name="delivery_type_radios"]' =&gt; array('value' =&gt; 0),
        ),
    ),
);
This makes it work:

   '#title' =&gt; 'bleh',


It kinda makes sense...