Why does it take so long for posts to show up?

Does anyone know? When we post on this section of allnurses.com your post has to be approved before showing up on the site. I've had posts go days before showing up while others aren't posted at all. If you post under the General Nursing section your post shows up immediately. Why the difference here? It makes for very disconnected dialog when posts do not show up but many hours or a day or two later. What's the rationale for approving posts in this section when other sections show up immediately?