The distributors and studio wanted this to have a 12A rating in the UK so the BBFC asked them to not only cut scenes out but adjust the sound levels at the "jump" scenes and even adjust some of the colour timing*
They did and that's how the movie was given the 12A rating in the UK (also happened in other countries). Apparently the Blu Ray/DVD release will be an "uncut" andfar scarier version
*taken from an interview with the head of the BBFC given to the Mayo and Kermode's film review podcast from BBC Radio 5 Live. You should all actually listen to this every week - free on itunes
