Just read the topic: http://wordpress.org/support/topic/71527 after searching for an answer to my problem.
My problem is: i am trying to use Ubernyms ( http://www.huddledmasses.org/jaykul/ubernyms-20/ ), which stores text to be replaced in the DB. The plugin messes up if one uses UTF-8 characters - chinese for example.
Looking in it's code i found nothing to justify the mess up but the functions update_option() and get_option(), which seem to be WP functions to deal with the DB.
As i wouldn't expect the plugin author to provide a fix for this, i thought i would ask here: is this a WP bug when dealing with the DB? This may answer a question in the above cited topic as to why one should care about how international characters are stored in the DB as long as they are displayed correctly.