I have a MySQL user called dump with the following perms:
GRANT USAGE ON *.* TO \'dump\'@\'%\' IDENTIFIED BY ...
GRANT SELECT, LOCK TABLES ON `mysql
I found the extra GRANT I needed!!
GRANT TRIGGER ON `myschema`.* TO 'dump'@'%'
Here you have the reference on the official doc: http://dev.mysql.com/doc/refman/5.5/en/privileges-provided.html#priv_trigger
The TRIGGER privilege enables trigger operations. You must have this privilege for a table to create, drop, or execute triggers for that table.