Phantom notifications?

I've got a problem with the desktop version.  I've got the preferences set to show badges for new messages so the icon in my dock (on my Mac) shows there are 6 new messages.  But, I can't find them!  I've gone through all the servers I belong to, I've marked everything as read, and yet the badge still shows 6 new messages! I don't know where these "new messages" are, or if they even exist, or if the badge just isn't resetting properly.  Can anyone help??