Radio button in a table row notice

Hi!

I am building a table and I'm trying to integrate some radio buttons in the table row like this:

          $row[] = array(
            'data' => array(
              '#type' => 'radio',
              '#title_display' => 'invisible',
              '#name' => 'radios_left',
              '#return_value' => $vid,
              '#default_value' => FALSE,
            ),
          );

but I get the following notice:

Undefined index: #value in /var/www/drupal/core/includes/form.inc on line 1147

However I noticed that if I just display the radio button on it's own (not in a table row) the notice dissapears and also the only way of making the notice dissapear when displaying radio button in a table row is to set the '#value' property.

So, I suppose this is a bug, since I should be able to set default value of radio button without being forced to set the value property.