mysqldump and triggers -> definer hostname

[Hans Meiser]

Hello,

mysql 5.1.40
i created some tables with triggers like described here:
http://dev.mysql.com/doc/refman/5.1/en/create-trigger.html
Now i do a mysqldump.
in trigger section the definer is written as: DEFINER=`mydbuser`@`%`
if i try to import the whole dump into the db mysql is rejecting with "you need the SUPER privilege".
if i change DEFINER=`mydbuser`@`%` to DEFINER=`mydbuser`@`localhost` so i can import the dump without errors.
i have another mysql-machine with 5.1.43
if i dump same sql on this machine then definer is written as DEFINER=`mydbuser`@`localhost` (not % )and reimport starts without the need of editing or errors.
Is this a kind of setting in mysql which chooses hostname at dumping triggers or may be a issue of version 5.1.40? I could not find fitting information.

Thanks,
Hans