I know you've answered this in another thread but can you give me your mysql version number.
Also for each of these tables can you run
SHOW FULL COLUMNS FROM tablename;
And list the results. There must be some columns being created with latin swedish collation.
As a possible fix ou could also try changing "CHARACTER SET `utf8`" to "DEFAULT CHARACTER SET `utf8`" at line 333 in administrator/components/com_jevents/controllers/config.php. You'd then need to delete and recreate the tables.
This is all very strange since the Joomla connection should be setting these default values for us already.