try adding that into the eCart coart object php file as well.
you may also need to set the client connection being used by php.
open the connection file in the connections folder, and find the last line, it will look like:
$<Connection Name> = mysql_pconnect($hostname_<Connection Name>, $username_<Connection Name>, $password_<Connection Name>) or trigger_error(mysql_error(),E_USER_ERROR);
where <Connection Name> is the name of the connection, add the following to the next line:
mysql_set_charset('utf8', $<Connection Name>);