Custom dropdown field appearing as multi-select field

Hello.

I followed the steps in this link to create a custom dropdown field:

HOWTO: Add a search field that searches another module « Sugar Developer Blog – SugarCRM

      array (
        'name' => 'ano_padv',
        'label' => 'Ano',
        'type' => 'enum',
        'default' => true,
        'options' => $dropdown_ano,
        'width' => '10%',
      ),

The only major difference to what I done is that I put the 'enum' type to the field in searchdefs.php to display it as a dropdown, but it displays as a multi-select field.

But as I know from SugarCRM, 'enum' is for single dropdown, and 'multienum' is for multi-select field.

So, what I'm doing wrong?

I'm using SugarCRM Community 6.5.22 with Google Chrome browser, and PHP 5.5.9.

Thanks.