Kasparov's main argument is that the computer made a move in game two that only a human being would have made.
*snickers* Or that a human would have programmed into a computer. Which particular move was it that Kasparov claims that only a human would have made? I've heard his claim, but I've never heard WHAT actual move it was. Now, here's the thing- you program a computer to win, and tell it how the pieces move. How many possible moves are there are on a chess board? It is a big database, but not insurmountable. That was just one more possible option, and the computer computed it had the best probability of a positive outcome.
I hear everyday "the computer screwed up" from people who can't bring themselves to admit they did it wrong and the computer did it right. And Kasparov has an ego that makes mine look tiny. Hmmm...
Oh, and some of the design, both hardware and software, was done about five miles from where I'm currently sitting. The word I've always heard around bars and restaurant tables about why Deep Blue was pulled apart was because it was too heat sensitive and had detectable performance degradation towards the end of the match. However, I will concede that that is a point in support for the conspiracy theorists. But if the thing was going to fry itself in under a thousand hours, IBM would bury it to save face. This is what the people inside IBM whom I know are saying, nothing about stuffing a bunch of chess masters in a box and not letting them out if they don't win. With custom components, I'd keep the stupid thing in a clean room-type enclosure to, with minimal EM interference.
If we are going to have a grassy knoll, let's find the trigger man. Or at least a smoking gnome. I will reiterate my first point- who were these chess masters?