Sort by country on a search result generates a db fatal error

Hi,

Steps to reproduce:
go to the search page
http://drupal.demo.civicrm.org/civicrm/contact/search

search (no criteria)

on the search result, click on the "country" header (to sort by country)

Result:
Sorry. A non-recoverable error has occurred.
DB Error: no such field

Database Error Code: Unknown column 'country' in 'order clause', 1054
Additional Details:

Array
(
[callback] => Array
(
[0] => CRM_Core_Error
[1] => handle
)

[code] => -19
[message] => DB Error: no such field
[mode] => 16
[debug_info] =>
INSERT INTO civicrm_prevnext_cache ( entity_table, entity_id1, entity_id2, cacheKey, data )
SELECT 'civicrm_contact', contact_a.id, contact_a.id, 'civicrm search d4aa8f8e30f8b40dffa83d3679348391_1614', contact_a.display_name
FROM civicrm_contact contact_a LEFT JOIN civicrm_address ON ( contact_a.id = civicrm_address.contact_id AND civicrm_address.is_primary = 1 ) LEFT JOIN civicrm_country ON civicrm_address.country_id = civicrm_country.id WHERE (contact_a.is_deleted = 0) GROUP BY contact_a.id ORDER BY country asc [nativecode=1054 ** Unknown column 'country' in 'order clause']
[type] => DB_Error
[user_info] =>
INSERT INTO civicrm_prevnext_cache ( entity_table, entity_id1, entity_id2, cacheKey, data )
SELECT 'civicrm_contact', contact_a.id, contact_a.id, 'civicrm search d4aa8f8e30f8b40dffa83d3679348391_1614', contact_a.display_name
FROM civicrm_contact contact_a LEFT JOIN civicrm_address ON ( contact_a.id = civicrm_address.contact_id AND civicrm_address.is_primary = 1 ) LEFT JOIN civicrm_country ON civicrm_address.country_id = civicrm_country.id WHERE (contact_a.is_deleted = 0) GROUP BY contact_a.id ORDER BY country asc [nativecode=1054 ** Unknown column 'country' in 'order clause']
[to_string] => [db_error: message="DB Error: no such field" code=-19 mode=callback callback=CRM_Core_Error::handle prefix="" info="
INSERT INTO civicrm_prevnext_cache ( entity_table, entity_id1, entity_id2, cacheKey, data )
SELECT 'civicrm_contact', contact_a.id, contact_a.id, 'civicrm search d4aa8f8e30f8b40dffa83d3679348391_1614', contact_a.display_name
FROM civicrm_contact contact_a LEFT JOIN civicrm_address ON ( contact_a.id = civicrm_address.contact_id AND civicrm_address.is_primary = 1 ) LEFT JOIN civicrm_country ON civicrm_address.country_id = civicrm_country.id WHERE (contact_a.is_deleted = 0) GROUP BY contact_a.id ORDER BY country asc [nativecode=1054 ** Unknown column 'country' in 'order clause']"]