Hi again,
I've found another bug with TinyMCE: when trying to edit a new category the edit-link in the browser:
http://wiki.fhb.fh-swf.de/wiki/index.php?title=Kategorie:Test&action=tin...
leads to the following errormessage:
Fatal error: Call to undefined method Article::openShowCategory() in /srv/www/htdocs/wiki/includes/EditPage.php on line 3222
Luckily, simply editing the browser-link to:
http://wiki.fhb.fh-swf.de/wiki/index.php?title=Kategorie:Test&action=edi...
solves the problem by opening the original editor for the category and it's not a thing that my normal users do every day...
Kate