utf-8,xampp and chtml

I have problem with greek characters and chtml-CActiveForm classess.
For example I write

<?php echo $form->labelEx($model,utf8_encode('τιτλε')); ?>

and there is ���������� -if I write

echo 'τιτλε'

is ok.
I use xampp 1.7.2.I also write chtml::encode().
What is wrong?