Resolution: Cannot Reproduce
Earlier today, moodle.org was unavailable for a short time whilst "upgrading" took place. We do not know which versions moodle.org was upgraded from and to, but we have now a symptom which I had already noticed on my local moodle 2.1 local test site when I upgraded, recently.
Whenever you post a new discussion or a reply on this site, when posting, you first get a
warning, and you have to click the Post to forum button once more.
Please not that the problem is not restricted to forum postings, but to any module/activity/etc. using the HTML editor.