Checked out some pictures of HBP on
www.mugglenet.com --
and then, checked out some of the film details, i.e., cast, etc,
here
and didn't realize the connection between HP and Narnia.
Professor Horace Slughorn in HP is the same actor who played Professor Kirke in Narnia-Lion, Witch, and the Wardrobe; Professor Flitwick is the same actor who played Nikabrik in Narnia-Prince Caspian.