Did you spot the deliberate error? No, me neither. What I've actually got is two versions of Book I - the UK version and an American edition. For some unfathomable reason the American publishers have changed the name of the first book. Why they think 'The Golden Compass' is a better title than 'Northern Lights' is beyond me. Why the author and copyright holder let them do it is something else again.
I remember that 'Harry Potter And The Philosopher's Stone' was published in the US as 'Harry Potter And The Sorcerer's Stone'. I can possibly understand that because 'Philosopher' is a very big word, and it is spelled incorrectly. If 'sulphur' is 'sulfur', then surely 'philosopher' should be 'filosofer'. But I digress.
I'm halfway through Book II, and enjoying it immensely. Wonderful stuff.