Thanks very much for all your advice. I'm trying to find out more about Madhur Jaffrey's books, and I am a bit confused over all these different titles too. I am thinking of buying the Ultimate book as you suggest, and want to draw your attention to some more "duplicates" :
Curry Easy is the same as At Home with Madhur Jaffrey: Simple, Delectable Dishes from India, Pakistan, Bangladesh, and Sri Lanka
Madhur Jaffrey's Foolproof Indian Cookery (Foolproof Cookery) is the same asSimple Indian Cookery
If you've managed to identify any more - please share! Thanks Maz Maz for your help.