we was load data.sql, after load schema.sql into mysql database, and get error (images.sql had not been imported yet!! ):
localhost zabbix-trunk # cat database/mysql/data.sql | mysql -pQwestions zbx_trunk
ERROR 1452 (23000) at line 12049: Cannot add or update a child row: a foreign key constraint fails (`zbx_trunk`.`sysmaps_elements`, CONSTRAINT `c_sysmaps_elements_2` FOREIGN KEY (`iconid_off`) REFERENCES `images` (`imageid`))

because some records (inserted rows) have constraint keys. Need to add next rows:
SET foreign_key_checks = 0; in the begin
and
SET foreign_key_checks = 1; in the end

I think need consider this factor.