Another that bugged me was Northern Lights -> The Golden Compass. Apparently NL was too abstract for American audiences?
Oh and Harlequin -> The Archer's Tale.
According to Pullman that one wasn't really about an attempt at cultural adaptation, the title had been in flux and the US publisher had taken an early name for the upcoming series, "The Golden Compasses", and run with it before he settled on Northern Lights.
Not only did the American editors change the title, but the device in question – the alethiometer, which is not a compass – is made of brass not gold in the original text. The US editors basically changed it to gold to fit their created title.