At least that's what Scott Ott of Scrappleface is reporting. The text of the friendly but seemingly nutty Iranian president's letter is here. I can't really recommend that you read all of that letter; a skim will give you the, ah, flavor of it.
But back to Bush's reponse, as Scott see it. Here's a choice excerpt:
In your 18-page letter, you asked me more than 63 questions.
The answer is ‘No’.
Now, let me ask you a few questions.
1) When you’re alone in a room by yourself, what do you all talk about?
2) How many moons can you see from your planet?
3) Roughly how long will it be before your mothership returns?
Take your time. Feel free to use the back of the paper to record your answers.
George W. Bush, POTUS
Read the whole thing. It'll brighten your day.