I searched lots of forums for this already:
did anybody notice, that the wysiwyg-editor (I tried tinymce and mosce) does not work at all on an international domain name with firefox?
error message in popup while trying to use any funktion like "make link" or "insert image":
punnycode in live-site is correct:
besides this in IE everything works fine.
of course I have newest firefox version and idn plugin.