Nobody knows which DBMS you're using.
MySQL supports out of the box UTF-8, and
phpBB does the same (as you can see with your own post: characters are perfectly stored). Changing the database table column type is the wrong approach.
But since your registration process doesn't allow non-ASCII characters for a username I don't understand why you are wanting them anywhere else then:
As per
http://www.maxko-forum.info/viewtopic.p ... 26#p217326 phpBB is not the problem, since the preview still displays characters as expected. You need to tell us your DBMS (and which content the variable
$dbms
has in your
/config.php).