Meditations 6: A problem with dualism

In part 6 of Meditations, Descartes talks more about dualism and the distinction between mind and body. He talks about how he knows that the mind exists ("I think therefore I am"), but he has to work through an argument to prove that the body exists (Matt talks about that in his first post on this section).  Once Descartes is satisfied that both the mind and the body exist, he has to work out a way to justify the connection his soul has with his particular body. This is a problem because if all minds are distinct from all bodies, then there is no way to account for things like hunger, thirst, pleasure, and pain. If my mind is independent from my body, like Descartes suggests, that why does my mind only recognize pain that is inflicted upon my body? What accounts for the joining of a mind with a body? Further, if every living body is paired with a soul, are the two really distinct? Descartes questions this...

"As for the body which by some special right I called 'mine,' my belief that this body, more than any other, belonged to me had some justification. For I could never be separated from it, as I could from other bodies; and I felt all my appetites and emotions in, and on account of, this body; and finally, I was aware of pain and pleasurable ticklings in parts of this body, but not in other bodies external to it. But why should that curious sensation of pain give rise to a particular distress of mind; or why should a certain kind of delight follow on a tickling sensation? Again, why should that curious tugging in the stomach which I call hunger tell me that I should eat, or a dryness of the throat tell me to drink, and so on? I was not able to give any explanation of all this, except that nature taught me so. For there is absolutely no connection (at least that I can understand) between the tugging sensation and the decision to take food..."

"Nature taught me so" is the best explanation I can find for Descartes' response to this problem. He goes on from this section of part 6 to talk about the mind-body distinction in a very matter-of-fact way. He says that he knows himself to be a thinking thing that does not exist in space, and he has "a distinct idea of body, in so far s this is simply an extended, non-thinking thing." He comes to the conclusion that he is distinct from his body and that he can exist without it. 

I'm not convinced.