Today I ran into a very very mad bug: conditional_fields.module did not correctly work in IE, as discussed in this issue:
https://www.drupal.org/node/1373656
But as I later found out and posted here this problem is based on the FAPI #states API!
You should never forget to cast (integer) values to string to make form field dependencies work in IE (using the module or the FAPI #states API directly).
Example:
/**
* Implements hook_form_node_form_alter().
*/
function HOOK_form_node_form_alter(&$form, &$form_state, $form_id) {
if ($form_id === 'my_node_form') {
$form['title']['#states'] = array(
'visible' => array(// action to take.
':input[name=field_kat[und]]' => array(
// String cast is important for IE compatibility!!!
array('value' => (string) 11),
)
),
);
}
}
?>
Hope you found this blog entry before searching around for hours like me...
Finally the bug should be fixed in Drupal 7 Core:
https://www.drupal.org/node/1962800#comment-9762429
