Wysiwyg custom attribute with cms directives is not working

Custom attribute with wysiwyg cannot be simply outputted.

If it contains cms directives {{media url="wysiwyg/images_2_.jpg"}}, it should be preprocessed with catalog/output helper.

<?php
    $product = $this->getProduct();
    $attribute = $product->getYourAttribute();
    $attributeName = 'your_attribute_name';
    echo $this->helper('catalog/output')->productAttribute($product, $attribute, $attributeName);
?>

Important

Check that in sql upgrade your custom attribute was created correctly with all necessary properties

$this->addAttribute('catalog_category', 'custom_attribute', array(
    'group'                    => 'General',
    'input'                    => 'textarea',
    'type'                     => 'text',
    'label'                    => 'Custom attribute',
    'backend'                  => '',
    'visible'                  => true,
    'required'                 => false,
    'visible_on_front'         => true,
    'global'                   => Mage_Catalog_Model_Resource_Eav_Attribute::SCOPE_GLOBAL,
    'wysiwyg_enabled'          => true,
    //these attribute is very important for processing cms directives
    'is_html_allowed_on_front' => true,
));

Also make sure that "Allow Dynamic Media URLs in Products and Categories" in System->Configuration->Catalog->Frontend is set to "yes".