Join not working

Hi there,

I'm writing a views handler where I join a table. Unfortunately, this does not work.
A short explanation (note that the module and the base table have the same names):

In mymodule_views_data():

$data['mybasetable]['table']['base'] = array(
'field' => 'uid',
'title' => 'my title',
'help' => 'my help'
);
?>

I want to join a (custom) user table. "mybasetable" has a uid field, and also the table i want to join has. My attempt to join in mymodile_views_data():

	$data['mybasetable']['table']['join'] = array(
		  'myusertable' => array(
			'left_table' => 'myusertable',
   	        'left_field' => 'uid',
	        'field' => 'uid',        
	      ),
	     );

Now i want to have a field available in my view: "account", which is a field in "myusertable". Code in _data():

	$data['mybasetable']['account'] = array(
		'title' => t('Account-ID'),
		'help' => t('Account-ID'),
	  	'field' => array(
	    	'handler' => 'views_handler_field_mybasetable_account',
	    	'click sortable' => TRUE,
	  	),
	  	'filter' => array(
	    	'handler' => 'views_handler_filter_mybasetable_account',
	  	),
	     'relationship' => array(
         'base' => 'myusertable',
         'field' => 'account',
         'handler' => 'views_handler_relationship_mybasetable_account',
        'label' => t('A Label'),
	     ),
	);

Now, in hook_handlers():

[..]
'views_handler_relationship_mybasetable_account' => array('parent' => 'views_handler_relationship'),
[..]

and finally in the handler file views_handler_relationship_mybasetable_account.inc:

class views_handler_relationship_mybasetable_account extends views_handler_relationship {
	function construct() {
		parent::construct();
	}
	
}

When I clear all caches and preview the view (where the field "account" is added), I get:

user warning: Unknown column 'mybasetable.account' in 'field list' query: [...]

... and the joined table is missing in the query.

Does anyone have an idea?

Thanks a lot,
Stefan