It’s been a summer drought which has left film-lusters like us weeping into our Back To The Future comfort blankies. For a whole month, no opening film has grossed more than £4 million. This has been due to a number of things; the World Cup, the glorious un-British sunshine, as well as because, well, the films out at the moment are a bit crud. But it looks like Shrek 4 has changed all that.