Creating an attribute programatically, but is never visible on front

I’m creating a new attribute via install, this is the code:

$installer = $this;
    $installer->startSetup();

    // Add new Attribute group
    $groupName = 'Atributos';
    $entityTypeId = $installer->getEntityTypeId('catalog_product');
    $attributeSetId = $installer->getDefaultAttributeSetId($entityTypeId);
    $installer->addAttributeGroup($entityTypeId, $attributeSetId, $groupName, 0);
    $attributeGroupId = $installer->getAttributeGroupId($entityTypeId, $attributeSetId, $groupName);

    $installer->addAttribute("catalog_product", "prd_alto", array(
        'group'             => 'Atributos',
        'label'             => 'Alto Producto',
        'input'             => 'text',
        "type"              => 'varchar',
        'required'          => false,
        'visible'           => true,
        'visible_on_front'  => true,
        'filterable'        => false,
        'searchable'        => false,
        'comparable'        => false,
        'user_defined'      => true,
        'is_configurable'   => false,
        'global'            => Mage_Catalog_Model_Resource_Eav_Attribute::SCOPE_GLOBAL,
        'note'              => '',
    ));
$installer->endSetup();

As you can see, I’m first creating a new group and then asigning a new attribute to it, this works fine.
However, the attribute that is created has always the option “is_visible_on_front” deactivated.
I’ve tried with true and 1, neither of them worked.
I can’t see why I can’t set this attribute to be visible on front. Please help!!