First off, this has been discussed quite a lot. Please learn to use the
Search feature.
Second, the reason you can't send new custom sounds is because the server
is down. The first time you send a sound, it uploads it to the server once, then you can play it whenever you want. Your old sounds are already on the server, so you can still send them.
Although, if the server's down, I'd imagine you wouldn't be able to send
any custom sounds... someone can correct me if I'm wrong.
So to summarize, there's nothing wrong with your settings, you'll just have to wait until the server is back up