To avoid output problems in non-latin characters you should add this line in a msyqli query (i.e. after $db = mysqli_connect($db_host, $db_user, $db_password, $db_name);):
mysqli_set_charset($db, 'utf8');
#1265 – Data truncated for ENUM/SET column
It’s a strange error, because it’s impossible that a ENUM or SET value exceeds the right width.
I managed to fix this error converting the field to utf8 and then I converted the whole table to utf8:
ALTER TABLE yourtable CONVERT TO CHARACTER SET utf8;