AHAH bug with IE - new information

Any AHAH form with a 'select' element as the second element seems to generate an error on IE 6 or 7. FF, Safari, and Chrome work OK. (http://drupal.org/node/321323).

What are the steps required to reproduce the bug?
Create a form like as shown below:
What behavior were you expecting?
Check the checkbox results in ahah callback supplying new form.

What happened instead?
On IE, page error and the new form is not loaded. For complete working code to debug this problem see: http://drupal.org/node/321323

Here is the form:

    $form['test'] = array (
    '#prefix' => '<div id="'.TEST_WRAPPER.'">',
    '#suffix' => '</div>',
    '#type' => 'fieldset',
    '#title' => 'Test Module...', 
    '#tree' => TRUE,
    );

    $form['test']['button'] = array (
    '#type' => 'checkbox',
    '#name' => 'Test Submit Button',
    '#title' => 'Push Me',
    '#id' => 'unique-test-id',
    '#ahah' => array(
        'path' => TEST_PATH,'event' => 'click','wrapper' => TEST_WRAPPER,
        'progress' => array('type' => 'bar', 'message' => t('Grinding...')),
      ),    
    );
    $form['test']['action'] = array (
        '#type' => 'select',
        '#name' => 'action',
        '#title' => t('Action To Perform'), 
        '#options' => array('one'=>'1','two'=>'2'),
         '#default_value' => '1',
        '#description' => 
     t('A select as second element'),
);
    return $form;