missing pending requests in mailman administrative database

The administrator/moderator of the list gets a message saying that there is a post pending approval. However, when he logs in and clicks "Tend to pending moderator requests" there is nothing there. Basically we keep getting "pending" notices but the queue is empty. It had been working and no settings were changed.

When a message is sent to a mailing list there are no pending requests but if sent to a list and some members of the list have the moderation bit set as off they receive the message .

How can i solve this?
thanx in advance