You can also have a look at
these lines in
includes\classes\order.php
line 138
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$customer_address_query = tep_db_query("select c.customers_firstname, c.customers_lastname, c.customers_telephone, c.customers_email_address, ab.entry_company, ab.entry_street_address, ab.entry_suburb, ab.entry_postcode, ab.entry_city, ab.entry_zone_id, z.zone_name, co.countries_id, co.countries_name, co.countries_iso_code_2, co.countries_iso_code_3, co.address_format_id, ab.entry_state from " . TABLE_CUSTOMERS . " c, " . TABLE_ADDRESS_BOOK . " ab left join " . TABLE_ZONES . " z on (ab.entry_zone_id = z.zone_id) left join " . TABLE_COUNTRIES . " co on (ab.entry_country_id = co.countries_id) where c.customers_id = '" . (int)$customer_id . "' and ab.customers_id = '" . (int)$customer_id . "' and c.customers_default_address_id = ab.address_book_id");
$customer_address = tep_db_fetch_array($customer_address_query);
----
Please try to run the query in phpmyadmin and if you are not getting the country in the output, you know whats wrong!