Cactivedataprovider Column Not Found

Hi,

I'm a bit confused about the different behaviour between ::model() and CActiveDataProvider. Using the same criteria object:

$crit = new CDbCriteria();
$crit->with = array( 'categoryHasLanguages' );
$crit->select = array(
	'id',
	new CDbExpression('IFNULL(categoryHasLanguages.translation, t.name) AS name'),
	'slug'
);
$crit->addColumnCondition( array(
	'id_organization' => $organization,
	'categoryHasLanguages.id_language' => $lang,
) );

Calling

Category::model()->findAll( $crit );

works, but calling

$dataProvider = new CActiveDataProvider( 'Category', array( 'criteria' => $crit, ) );

, doesn't. I know how to get it working, adding

$crit->together = true;

, but I'm asking if someone can explain this to me