I figured it out. I'm not a 'participant', merely a 'follower'.
posted message: Had a rough user experience here on P2PU.org tonight. I couldn't figure out where to post comments... to anything. Is the feature disabled? for just me? for just my courses? It would be great - like in standard forum software - if it gave you a status message like, "You can't post here" or "Login to comment" or "Your status is pending moderation". Frustrated and slightly late, Newman