In Form - Second level hs items not working on IE

Hi,

First of all i would like to thank you for this module.

I am using hs in Drupal form and the problem occurs on IE (FF is fine).
The hs form dropbox which has second level is not displayed in IE (see picture attached).
the hs form dropbox which has only one level terms (i.e. flat hierarchy) is working fine.

I have attached the relevant code from the form.

Please advice.

    $form['nickname'] = array (
        '#type' => 'textfield',
        '#title' => t('Name'),
        '#description' => t('English only'),
        '#prefix' => '<table style="margin-top: 0px; margin-bottom: 0px;"><tr><td width=17%>',
        '#suffix' => '</td>',
        '#size' => 15,
    );
    $form['experience'] = array(
        '#type' => 'hierarchical_select',
        '#title' => t('Experience'),
        '#description' => t('In years'),
        '#prefix' => '<td width=17%>',
        '#suffix' => '</td>',       
        '#size' => $size,
        '#config' => array(
            'save_lineage' => 1,
            'enforce_deepest' => 1,
            'resizable' => 0,
            'module' => 'hs_taxonomy',
            'params' => array(
                'vid' => 2,
            ),
        ),
    );
    $form['category'] = array(
        '#type' => 'hierarchical_select',
        '#title' => t('Category'),
        '#description' => t('Speciality'),
        '#prefix' => '<td>',
        '#suffix' => '</td></tr></table>',
        '#size' => $size,
        '#config' => array(
          'save_lineage' => TRUE,
          'enforce_deepest' => TRUE,
            'resizable' => 0,
            'module' => 'hs_taxonomy',
            'save_lineage' => 1,
            'params' => array(
                'vid' => 1,
            ),
        ),
    );