Keynote not working with iPhone 3GS.

I have Keynote on my macbook, and have now bought keynote for my iPhone 3GS, because Keynote is claimed to work on it. Discover it will not work with a VGA connector so I spent more money on an Apple AV cable. It works with youtube, but NOT with Keynote! So while Keynote works on the 3GS I would have to give out binoculars to an audience. How can I get Keynote working with an iPhone 3GS and an AV cable? Or have I spent loads of money on a dead dogs and their leads?