Change default language

Hi,
I make a translation for Laconica to Romanian language but '''HOW CAN I CHANGE THE DEFAULT LANGUAGE !?'''

I change language configuration in config.php and language.php - '''it doesn`t work!'''

'''config.php'''
#$configsite?timezone? = 'Eastern European Time';
#$configsite?language? = 'ro_RO';

'''/lib/language.php'''
'ro' => array('q' => 1, 'lang' => 'ro_RO', 'name' => 'Romanian', 'direction' => 'ltr'),
'''
Not my translation is the problem'''. I change default language to 'de' (german) - '''it doesn`t work again'''!