My observation of the differences in titles is that it looks (from the examples given), like publishers use more dynamic sounding titles for the U.S. market than they do for the British market.

This is in keeping with the differences that I see in movies and television programs. The first season or two of "Red Dwarf" seemed more cerebral to me than subsequent seasons. When the show became popular in the U.S., it seemed like they jazzed it up with flashier colors and more explosions, which is pretty much what I would expect if they wanted to market to the majority of people in the U.S.

Carol