For the first few times, we have simply deleted the post that was periodically popping up under "moderation".. However, I have thought it be good to bring it up to your attention.
For some reason, every few weeks or longer, we will get a bunch of the same post to continue to pop up under moderation. Personally, I have rejected and even deleted them, but the same ones continue to pop back up.
So there you go, not sure what can be done, but I will leave them in moderation in case you like to take a dive at it...
Possible bug or not playing well with a certain plugin/component, not quite certain.
Let me know if I can give any further information..