[fw-db] Related tables reference error

Hello all,

I'm trying to setup a many-to-many relationship between "articles" and "keywords", but I keep getting the following error:

Fatal error: Uncaught exception 'Zend_Db_Table_Exception' with message 'No reference from table ArticlesKeywords to table Keywords' in......

Here is my code:

$articles = new Articles ( );

$rowset = $articles->find ( $id );

$rowset->current()->findManyToManyRowset('Keywords', 'ArticlesKeywords');

In Articles.php:

protected $_name = 'articles';

protected $_dependentTables = array('ArticlesKeywords');

In Keywords.php:

protected $_name = 'keywords';

protected $_dependentTables = array('ArticlesKeywords');

In ArticlesKeywords.php:

protected $_name = 'articles_keywords';

protected $_referenceMap = array (

'Keywords' => array (

'columns' => array ('keyword_id' ), 

'refTableClass' => 'Keywords', 

'refColumns' => array ('id' ) ), 

'Articles' => array (

'columns' => array ('article_id' ), 

'refTableClass' => 'Articles', 

'refColumns' => array ('id' ) ) 

);

Here is a simplified ER Diagram of the database:

Articles:

id int(11) PK

....

Keywords:

id int(11) PK

....

ArticlesKeywords

id  int(11) PK

article_id int(11) FK

keyword_id int(11) FK

Does anyone have any idea how else I can troubleshoot or is my syntax incorrect?

Thank you,

Henry