This is why the Daniel Craig debut Bond movie Casino Royale came out in 2006, almost 40 years after the Peter Niven Casino Royale movie that isn't in the Bond movie continuity.
On a side note, due to licensing and other issues surrounding the Bond franchise, the movies were released in a different order than the books were written in. Casino Royale was the first of 11 novels and a number of short stories that revolved around James Bond.