[jQuery] Works in IE not FF?!

Hello!
I have buttoms with some letters like Å Ä and Ö. When you click at
them they should be pasted into a textarea. It works perfectly in ie 6
and 7 but not in firefox??!

$("input.infoga_tecken").click(function(){
                        $("textarea#gb_textarea").append($(this).val());
        return false;
});