Your primary user group was Former Staff Member... I moved it to Administrator.
Former Staff Member, however, did not have the "Moderate Posts" selection picked but the above is what I did to fix it. So why the moderation, I don't know..
On Former Staff Member Usergroup, of which both Seth (was) and OS (is) a part of and of which both complained of not being able to post due to their post having to be "moderated", the "Moderate Post (yes) (No)" selection is designated: No.
Therefore, why you cannot still post OS (while other Former Staff Members can), I don't know.