Would you fall out with Darth Vader?

George Lucas is clearly fearless as he has banned Darth Vader (David Prowse) from attending any more Star Wars conventions. Apparently David Prowse has said that he has been told he cannot attend any "Lucasfilm associated events" from now on, writing "The only thing I've been told is I've burnt too many bridges between Lucasfilm and
myself.". It seems this spat is at least partly due to money as David/Darth claims not to have been paid any residuals Return of the Jedi because according to LucasFilm the movie had yet to make a profit. The reason, according to Lucas Films, being that 'There is a big difference between having a share of the gross profit and having a share of the net profit. It is a huge difference in just one word. Sometimes, with net profit, with all the expenses and so on, it seems like you end up paying them.'. Hmm seems odd that one of the biggest grossing films of all time has yet to make net profit, I suppose it depends what overheads have been allocated to the film....