Trust me, the position was a draw. We burned no telling how many computer hours that night. And we had lots of GM players helping (Bruce Moreland and I burned most of the time it seems). And when told, Kasparov spotted it almost instantly. The problem is always a perpetual here, not just an "equal ...

Is that correct? You ran Crafty for 55 hours? :shock:

Here's what Critter-1.4 (8 threads) gives after about 1 hour:

23/67 59:31 32583304138 9124195 +0.00 axb5 Qxa8 Qc7 Rb1 Bd4 bxc5 Bxc5 Rxb5 Nd7 Qa4 O-O Qc2 f5 exf5 e4 Ng5 Rxf5 Ke1 Ndf6 Be2 Bf2+ Kd1 Bd4 Nh3 Ne3+ Bxe3 Bxe3 g4 Re5 Qb3 Rxd5+ Rxd5 ...

http://en.wikipedia.org/wiki/Nolot

Take a look at the problem #6:
rnbqk2r/1p3ppp/p7/1NpPp3/QPP1P1n1/P4N2/4KbPP/R1B2B1R b kq - 0 1
13... axb5!! offers a rook to keep the white queen out of play. 14.Qxa8 Bd4 15.Nxd4 cxd4 16.Qxb8 0-0! 17.Ke1 Qh4 18.g3 Qf6 19.Bf4 g5? (Ivanchuk found 19...d3 ...

I recently stumbled across the wikipedia article on the second game of the match:
However, it was discovered in 2007 by Internet analysis[7] that after 45...Qe3 46.Qxd6 Re8 47.Qd7+ Re7 48.Qc6 Qxe4 49.d6 Qd3+ 50.Kg1 Re8 51.Ra1 there is no perpetual check and the attack continues. The critical move ...