[bashbang]

I had the same problem with my moderation queue. It said I had 10 posts to be moderated, but there wasn't anything in the que. I ended up cleaing the queue of these ghost posts by:
1) temperarily shutting down the board
2) Clear the queue of any outstanding items
3) going into the mysql DB and deleting all the items in the queue:
mysql> delete from moderation;
4) turn the board back on.

I'm kinda new the whole vBulletin thing, so I'm not sure this is the "proper" way of doing things, but it solved my problem so I was happy.

PS: I don't know for sure, but I think the reason for the ghost moderation items is due to deleting a thread in one window, while the moderation page is open in another. This in itself creates a MySQL error and I suspect is the cause of the orphaned moderation items.