It turns out that whenever a user posts their first audio file to the portal, that user has to wait for audio moderators to check the first song and ok the user, making it possible for them to post on the portal further. Apparently there are too few moderators, they are all too busy, or there are just too many users to approve, creating quite the lag in production. I would be willing to bet it's actually a combination of these three things, maybe even more.
Oh well. All I can do is wait.
(audio mods, don't think I mean any disrespect or anything, I'm just being silly ;] Loooooove you guuuuuys.)