General usage questions
This came from an update to the website software we use for the forums. There is a fix, (discussed upstream at http://drupal.org/node/1356390 if you're interested in web development) which will be deployed to this website within a few days. I didn't notice the problem myself, so thanks for posting here so that it could be investigated and can be fixed here.
These appear to be changes made by the temporary admin that popped in and made things cracy for a few days.
I just want to clarify that the forum moderator issue is unrelated to this particular problem, as I do not think that enabling a user to edit his own posts is even something the forum moderator can do. It was a software bug that got introduced during routine updates, people who have moderator privileges didn't even notice because they can edit any post, and now it should hopefully be fixed soon :-).
Just one note more relevant to the general forum topic “Usage questions”: it seems that many responses to the first post in this thread have been themselves new, distinct threads which all talk about the same topic. Shouldn't each new thread be a distinct, unrelated “Usage question”? ;-)