mysql dump failure (1 reply)

after upgrading to mysql 5.5.27 my cron jobs are failing with an error

CRON:
$command = "mysqldump --add-drop-table -u $dbuser --password=$dbpwd $dbname | gzip > $filename";

ERROR:
mysqldump: unknown variable 'default-storage-engine=MyISAM'

here is the top section of /etc/my.cnf
[mysqldump]
quick
max_allowed_packet=16M
default-storage-engine=MyISAM
innodb_file_per_table=1


Thanks for any help.
jim