[TYPO3-mvc] model properties?

[Daniel Dimitrov]

Hey guys,
I'm trying to figure something out, but so far I'm unsuccessful :(
I have a simple Model class:
/**
 * A product
 *
 * @version $id:$
 * @scope prototype
 * @entity
 */
class Tx_Bwshop_Domain_Model_Products extends 
Tx_Extbase_DomainObject_AbstractEntity {
	/**
	 * the product's title
	 * @var string
	 */
	protected $title;

	/**
	 * the product's author_name
	 * @var string
	 */
	protected $author_name;

	/**
	 * the product's description
	 * @var string
	 */
	protected $description;

	/**
	 * the product's short description
	 * @var string
	 */
	protected $short_description;

	/**
	 * the product's volume
	 * @var string
	 */
	protected $volume;

	/**
	 * get the product's title
	 * @return string
	 */
	public function getTitle() {
//		var_dump($this);
		return $this->title;
	}

	/**
	 * get the product's short_description
	 * @return string
	 */
	public function getShortDescription() {
		return $this->short_description;
	}

	/**
	 * get the product's author_name
	 * @return string
	 */
	public function getAuthorName() {
		return $this->author_name;
	}

	/**
	 * get the product's title
	 * @return string
	 */
	public function getDescription() {
		return $this->description;
	}

	/**
	 * Sets the title of the product
	 *
	 * @param string $title of the product
	 * @return void;
	 */
	public function setTitle($title) {
		$this->title = $title;
	}

	/**
	 * Sets the author_name of the product
	 *
	 * @param string $author_name of the product
	 * @return void;
	 */
	public function setAuthorName($author_name) {
		$this->author_name = $author_name;
	}

	/**
	 * Sets the short_description of the product
	 *
	 * @param string $title of the product
	 * @return void;
	 */
	public function setShortDescription($short_description) {
		$this->short_description = $short_description;
	}
}

when I use findAll to get all data from the database a single object from 
the result looks like this:
object(Tx_Bwshop_Domain_Model_Products)#107 (8) {
    ["title:protected"]=>
    string(17) "ABCP"
    ["author_name:protected"]=>
    NULL
    ["description:protected"]=>
    string(11) "description"
    ["short_description:protected"]=>
    NULL
    ["volume:protected"]=>
    string(3) "100"
    ["_cleanProperties:private"]=>
    array(4) {
      ["title"]=>
      string(17) "ABCProblemAnalyse"
      ["description"]=>
      string(11) "description"
      ["volume"]=>
      string(3) "100"
      ["uid"]=>
      int(1056)
    }
    ["uid:protected"]=>
    int(1056)
    ["isClone:private"]=>
    bool(false)
  }

as you see the object has proteted properties such as short_description and 
author_name that are not added to the _cleanProperties.
Actually, why is the value set to NULL? Author_name and short_description 
are fields in the database and they are defined in my tca.php file like 
this:
	'author_name' => array (
			'exclude' => 0,
			'label' => 
'LLL:EXT:bw_shop/Resources/Private/Language/locallang_db.xml:tx_bwshop_domain_model_products.author_name',
			'config' => array (
				'type' => 'input',
				'size' => '30',
			)
		),
		'short_description' => array(
			'exclude' => 1,
			'label'   => 
'LLL:EXT:bw_shop/Resources/Private/Language/locallang_db.xml:tx_bwshop_domain_model_products.short_description',
			'config'  => array(
				'type' => 'text',
				'rows' => 5,
				'cols' => 30,
			)
		),


Any ideas what I do wrong?
Thanks,
Daniel