There's a new anti-spam feature that actually just seems to be a pain in the butt, as it screens comments that trigger the feature but does not notify either the person who left it or, if the comment was made in a community, any mods that the comment is there at all. The feature is automatically enabled on all journals and communities.
Here's more about it and how to disable it. *headdesk*
Caz, I disabled this on flesh_and_steel, you can put it back if you want.