Cannot choose state

I modified file:
ec_store/ec_store.localization.inc
and added polish states:
case 'PL':
$states[$country] = array(
'DO' => t('Dolnośląskie'),
'KP' => t('Kujawsko-Pomorskie'),
'LO' => t('Łódzkie'),
'LL' => t('Lubelskie'),
'LU' => t('Lubuskie'),
'ML' => t('Małopolskie'),
'MZ' => t('Mazowieckie'),
'OP' => t('Opolskie'),
'PP' => t('Podkarpackie'),
'PL' => t('Podlaskie'),
'PM' => t('Pomorskie'),
'SL' => t('Śląskie'),
'SW' => t('Świętokrzyskie'),
'WM' => t('Warmińsko-Mazurskie'),
'WP' => t('Wielkopolskie'),
'ZA' => t('Zachodniopomorskie'),
);
break;
When I prepared URL like:
http://mysite.com/ec_address/autocomplete/PL/O
I recived correct hint:
{ "OP": "opolskie" }
When I typed "O" or "Op" in state autocomplete textbox request link is:
http://mysite.com/ec_address/autocomplete/O or http://mysite.com/ec_address/autocomplete/Op (inspected using FireBug)

There is not country code like "PL".