That's true, and I do understand that when I say that it's unlikely that, given the chemistry in question, the conditions for life to arise are hard to come by. You can read all about it, just do a search on combinatorics and evolutionary biology I'm certain you'll be able to find the kinds of mathematical models I'm thinking of. At the moment I don't have time to put up any internet sources, but the books Quantum Evolution by Johnjoe McFadden and Darwin's Black Box by Michael J Berthe examine the probabilities of catalyzing the fundamental chemicals of known biology; one estimate, I believe it referred to types of nucleic acids, put the probability of the production any of the fundamental varieties of acid (DNA, mRNA, tRNA, etc.) at one in 6^160, that's a 10 followed by 109 zeroes, and I believe that probability refers to the timeframe within which single-celled organisms are thought to have originated. Earth hasn't had the time for this type of reaction to be 'likely.' It is a possibility, but not a plausible one, given our understanding of Earth at the time of protogenesis (the origin of the first cells or whatever DNA and RNA originally used to propogate themselves.) As soon as I'm back from my evening classes I'll look up the details for you; chemists have been crunching these numbers since Watson and Crick, guys.
I was disappointed when I first read about this myself. But hey, anthropocentric universe; we're here today, so DNA must have come up somewhere! There's no need to fret just because Earth isn't a good candidate.
~Joe
PS - Titan is a moon. I believe it is a moon of... Saturn? Jupiter? One of the bigger planets in our solar system. Anyhow, Titan, and one of her sister moons, (is it Ganymede?) are likely candidates for places harboring extraterrestrial life, as they have liquid oceans of water (maybe ammonia) and other conditions thought to be helpful for raising living things.