HAS_MANY relation and display in CGridview

I have got a table relation of HAS_MANY like this

public function relations() {

    // NOTE: you may need to adjust the relation name and the related


    // class name for the relations automatically generated below.


    return array(


        'sinaisvitais' => array(self::HAS_MANY, 'Sinaisvitais', 'idUtente'),


        'idEnf0' => array(self::BELONGS_TO, 'Enfermeiro', 'idEnf'),


        'idServico0' => array(self::BELONGS_TO, 'Servico', 'idServico'),


        'idDieta0' => array(self::BELONGS_TO, 'Dieta', 'idDieta'),


    );


}

And my Search function is declared like this

public function search() {

    // @todo Please modify the following code to remove attributes that should not be searched.





    $criteria = new CDbCriteria;





    $criteria->compare('idUtente', $this->idUtente);


    $criteria->compare('idEnf', $this->idEnf);


    $criteria->compare('idServico', $this->idServico);


    $criteria->compare('nome', $this->nome, true);


    $criteria->compare('idade', $this->idade);


    $criteria->compare('dataNasc', $this->dataNasc, true);


    $criteria->compare('dataInternamento', $this->dataInternamento, true);


    $criteria->compare('morada', $this->morada, true);


    $criteria->compare('idDieta', $this->idDieta);


    $criteria->compare('dataIntervencao', $this->dataIntervencao, true);


    $criteria->compare('sondaVesical', $this->sondaVesical);


    $criteria->compare('ecd', $this->ecd);


    $criteria->compare('idSinaisVitais', $this->idSinaisVitais);


    $criteria->compare('riscoQueda', $this->riscoQueda);


    $criteria->compare('riscoAlergia', $this->riscoAlergia);


    $criteria->compare('riscoTransfusao', $this->riscoTransfusao);


    $criteria->compare('riscoMultiRisco', $this->riscoMultiRisco);


    $criteria->compare('obsQuadro', $this->obsQuadro, true);


    $criteria->compare('obs', $this->obs, true);





    return new CActiveDataProvider($this, array(


        'criteria' => $criteria,


    ));


}

My controller is declared like this

public function actionAdmin() {

    $model = new Utente('search');


    $model->unsetAttributes();  // clear any default values


    if (isset($_GET['Utente']))


        $model->attributes = $_GET['Utente'];


    $this->render('admin', array(


        'model' => $model,


    ));


}

And my Gridview is declared like this

$this->widget(‘zii.widgets.grid.CGridView’, array(

'id' => 'utente-grid',


'dataProvider' => $model->search(),


'filter' => $model,


'columns' => array(


    //'idUtente',


    array('name' => 'idEnf0', 'header' => 'Enfermeiro', 'value' => '$data->idEnf0->nome'),


    array('name' => 'idServico0', 'header' => 'Servico', 'value' => '$data->idServico0->nome', 'filter' => CHtml::activeTextField($model, 'idServico')),


    array('name' => 'nome', 'header' => 'Nome', 'value' => '$data->nome'),


    array('name' => 'idade', 'header' => 'Idade', 'value' => '$data->idade'),


    array('name' => 'dataNasc', 'header' => 'Data Nascimento', 'value' => '$data->dataNasc'),


    array('name' => 'idDieta0', 'header' => 'Dieta', 'value' => '$data->idDieta0->nome'),


    array('name' => 'dataInternamento', 'header' => 'Data Internamento', 'value' => '$data->dataInternamento'),


    array('name' => 'obsQuadro', 'header' => 'Quadro', 'value' => '$data->obsQuadro'),


    array('name' => 'obs', 'header' => 'Observações', 'value' => '$data->obs'),


    array('name' => 'sinaisvitais', 'header' => 'Sinais Vitais', 'value' => '$data->sinaisvitais->tas'),

When I try to access sinaisvitais->tas i get the following error

htmlspecialchars() expects parameter 1 to be string, array given

C:\xampp\htdocs\yii\framework\web\helpers\CHtml.php(158): CHtml::renderAttributes(array("name" => "Utente[sinaisvitais]", "type" => "text", "value" => array()))

All the other relations of 1:N work just fine… Can anyone help please… Many thanks.