http://www.bbc.com/news/magazine-35008573

This is more on CP's non-release in China. The author - like Anon - notes all the mentions of ghosts in Chinese literature and cinema. He thinks the sex scene (and incest theme) might have been a real reason CP wasn't released in China.

If it was more for the sex scene, my response would be: FOR THAT? For two seconds of arse, implied cunnilingus, a bit of around-the-world hip. It's not integral - cut it and give the movie a chance in one of the largest box office markets on the planet.