Sorry Munden, havent got an answer, but I was intrigued by darths answer making a reference to the question "Animals beginning with N". this rang some bells because about a year ago I was doing this riddle (see link below) and when you get to No 5 you should have 4 as your current total, which would then equal D then you should think of Denmark then you would think of a animal that begins with an E and so on and so on. But thicky here picked E as the 4th letter of the alphabet and then thought of England and then had to choose an animal beginning with N, well I was stumped for ages (20 mins) so began to e-mail around a few friends as this was before I was an Answerbanker, I got some answers but also questions about why I wanted to know this, when I explained to one of them why,they howled with laughter because they had done the riddle and knew that I had cocked it right up. I assume that other thickies around the country did the same and plagued the answerbank with the same seemingly obscure question. Sorry about that Munden, hope you get your catering answer, and sorry to answerbankers for wasting the last 45 seconds of your lives.
http://www.geocities.com/SiliconValley/Horizon/510
0/riddle.html