In my logs folder I found a log today with this error:

[30-Dec-2013 11:31:50 America/New_York] PHP Fatal error: 1267:Illegal mix of collations (latin1_swedish_ci,IMPLICIT) and (utf8_general_ci,COERCIBLE) for operation '=' :: SELECT zone_id
FROM zones
WHERE zone_country_id = 73
AND zone_code = '�SAVOIE'
OR zone_name = '�SAVOIE'
LIMIT 1 in /home/mywebsite/includes/classes/db/mysql/query_factory.php on line 120

I believe this error was created when a customer was trying to place an order. Any idea what is causing this error? or even better, how to fix it?