I did not had a local.xml file  so I make one :                                                 

     <?xml version="1.0" encoding="UTF-8"?>
    <!--
    /**
     * local.xml
     *
     * Local layout modifications for our local theme
     *
     * @category    design
     * @package     my_theme_default
     * @copyright   Copyright (c) 2011 Magebase.
     */
    -->
    <layout version="0.1.0">
    <catalog_product_view>
       <reference name="product.info">
          <block type="catalog/product_view_attributes" name="product.attributes" as="additional" after="description"/>
       </reference>
    </catalog_product_view>
    
    </layout> 
           
    
    The problem is that the attributes attributes disapeared