I have made a discovery! I just finished watching Ep. VI, the new edition, with Hayden Christensen as a force ghost at the end. (First, he doesn't look old enough to be about 40 years old, but that's another story).

What I did notice, was that his name wasn't in the ending credits, even though he was clearly (transparent) in the film. It's no big deal, he has only a few seconds on screen, but still, they did edit him in that movie to then forget to put his name in the credits.