Francois,
Have you tried wiping the game and reloading? To me this problem does sound serious, but you seem to be the only one with the problem. At this stage solving the problem would be number one, although I feel for you having to dump an excellent campaign, I'm a campaigner myself.
I'm curious when did this ghost problem appear? How far along in the campaign? In my experience, problems of this nature usually manifest themselves in the opening stages of a started game.
