Why, when Qui-gon Jinn dies, does he not disappear as Yoda and Obi Won do? Here's a sudden, out of the blue theory that--as far as I know--I am the first to hold (maybe a google search will prove otherwise): Qui-Gon Jinn holds onto life, rather than focussing on letting it go, and so his body perishes, but his spirit remains joined to this world. He comes back--as Luke Skywalker.
Just a thought. I'm not big on afterlife in general (once you're dead, you're dead), but if Tolkien's elves can reincarnate, why not Qui Gon? I'll admit, it's wacky, but then, so are Ewoks.
If I'm wrong, its probably for the best. If I'm right--you heard it here first!
UPDATE: I wonder how easy it would be to present this idea in a movie; in a book it would be far easier. Maybe it's off. Still, if I were right, a number of structural effects would take place: the entire Star Wars movie cycle would be bookmarked by the figure of Qui-Gon. Also, Luke's belief in his father would balance the faith of Qui-Gon in Anakin. In short, there would be structural "balance." On the other hand, the original trilogy was better as a free-standing unit, I must say. The changes that have been done to squeeze the original three movies into harmony with the prequels are harmful to the integrity of the earlier, and better, movies.