English writer Kyril Bonfiglioli wrote a trio of well-received comic thrillers in the 1970s that were compared favorably to the works of P.G. Wodehouse. Their hero, Lord Charlie Mortdecai, was an adventurous but not very competent aristocratic art dealer who relied on his preposterously loyal manservant Jock Strapp to keep him out of danger.
Johnny Depp isn’t bad as the film version of the character, Gwyneth Paltrow is lovely and appealing as his wife, Paul Bettany makes a good Jock, and the rest of the cast is fine as well.
So I can’t put my finger on why this movie doesn’t work. It isn’t awful, but it just isn’t very funny, and most reviewers seem to agree. The trailer, on the other hand, isn't bad: