In game 46,
[Event "step_2-KO-tour"]
[Site "The Base"]
[Date "2012.08.21"]
[Round "2.1"]
[White "Stockfish 2.2.2 JA SSE42 x4"]
[Black "Critter 1.6a 64-bit x4"]
[Result "0-1"]
[ECO "B12"]
[EventDate "2012.08.16"]
[EventType "tourn"]
[PlyCount "158"]
[TimeControl "40/2400:40/2400:2400"]
something went wrong,
Stockfish in a winning endgame (+327) "sacrificed" its rook (63. Ka5) and lost

Looks like a bug in Stockfish(?)
[d]8/8/2k5/3R4/1K4p1/6P1/8/8 w - - 0 63
[Event "step_2-KO-tour"]
[Site "The Base"]
[Date "2012.08.21"]
[Round "2.1"]
[White "Stockfish 2.2.2 JA SSE42 x4"]
[Black "Critter 1.6a 64-bit x4"]
[Result "0-1"]
[ECO "B12"]
[EventDate "2012.08.16"]
[EventType "tourn"]
[PlyCount "158"]
[TimeControl "40/2400:40/2400:2400"]
{Intel(R) Xeon(R) CPU W5580 @ 3.20GHz 3198 MHz W=33.4 plies; 6,
266kN/s; Strong2012.ctg B=30.1 plies; 7,634kN/s; Strong2012.ctg} {+0.00} 1.
e4 {[%eval 0,0]} 1... c6 {[%eval 0,0]} 2. d4 {[%eval 0,0]} 2... d5 {[%eval
0,0]} 3. e5 {[%eval 0,0]} 3... Bf5 {[%eval 0,0]} 4. Nf3 {[%eval 0,0]} 4... e6
{[%eval 0,0]} 5. Be2 {[%eval 0,0]} 5... Ne7 {[%eval 0,0]} 6. O-O {[%eval
56,25]}{[%emt 0:01:02]} 6... c5 {[%eval 30,21]}{[%emt 0:02:07]}{(Sg6)} 7. Na3
{[%eval 44,25]}{[%emt 0:02:18]}{(dxc5)} 7... cxd4 {[%eval 21,20]}{[%emt
0:01:38]}{(Sec6)} 8. Bg5 {[%eval 52,26]}{[%emt 0:01:52]}{(Sb5)} 8... a6
{[%eval 14,22]}{[%emt 0:01:06]} 9. Nxd4 {[%eval 88,26]}{[%emt 0:00:11]} 9...
Be4 {[%eval 8,22]}{[%emt 0:01:26]}{(Dd7)} 10. c4 {[%eval 76,26]}{[%emt
0:01:04]} 10... h6 {[%eval 36,20]}{[%emt 0:00:14]}{(Dd7)} 11. Qa4+ {[%eval
84,24]}{[%emt 0:01:56]} 11... Nd7 {[%eval 20,20]}{[%emt 0:00:14]} 12. Be3
{[%eval 125,25]}{[%emt 0:01:40]} 12... dxc4 {[%eval 30,20]}{[%emt 0:00:53]}
{(Db8)} 13. Nxe6 {[%eval 181,28]}{[%emt 0:01:35]}{(Sxc4)} 13... fxe6 {[%eval
142,20]}{[%emt 0:01:57]} 14. Nxc4 {[%eval 208,29]} 14... Nd5 {[%eval 145,20]}
{[%emt 0:00:57]} 15. Nb6 {[%eval 210,29]}{[%emt 0:00:53]} 15... Bf5 {[%eval
138,21]}{(Sxe3)} 16. Rad1 {[%eval 246,27]}{[%emt 0:00:57]} 16... Be7 {[%eval
151,22]}{[%emt 0:01:56]} 17. Nxa8 {[%eval 242,31]} 17... O-O {[%eval 144,22]}
{[%emt 0:00:54]}{(Dxa8)} 18. Bf3 {[%eval 234,28]}{[%emt 0:01:11]} 18... Nxe5
{[%eval 148,23]} 19. Bxd5 {[%eval 234,21]} 19... exd5 {[%eval 148,22]} 20. Qb3
{[%eval 234,29]}{[%emt 0:01:17]} 20... Be4 {[%eval 147,22]} 21. Nb6 {[%eval
246,30]}{[%emt 0:01:41]} 21... Qd6 {[%eval 158,23]}{[%emt 0:02:20]} 22. Rxd5
{[%eval 222,30]}{[%emt 0:00:20]} 22... Bxd5 {[%eval 158,22]} 23. Nxd5 {[%eval
230,29]}{[%emt 0:01:12]} 23... Kh8 {[%eval 151,23]}{[%emt 0:00:18]}{(Kh7)}
24. Qxb7 {[%eval 234,29]}{[%emt 0:01:42]} 24... Ng4 {[%eval 160,23]}{[%emt
0:00:59]} 25. g3 {[%eval 246,29]}{[%emt 0:00:11]} 25... Rb8 {[%eval 160,24]}
{[%emt 0:01:46]} 26. Qa7 {[%eval 262,32]}{[%emt 0:01:56]} 26... Nxe3 {[%eval
165,24]} 27. Nxe3 {[%eval 262,31]}{[%emt 0:03:13]} 27... Re8 {[%eval 167,26]}
28. Rd1 {[%eval 262,30]}{[%emt 0:01:13]}{(b3)} 28... Qe5 {[%eval 167,25]}
{[%emt 0:02:26]}{(Dg6)} 29. Qd4 {[%eval 266,27]}{[%emt 0:01:17]}{(Dd7)}
29... Qb5 {[%eval 168,25]}{[%emt 0:04:09]}{(Dxd4)} 30. Qd7 {[%eval 278,30]}
{[%emt 0:02:52]} 30... Bc5 {[%eval 172,27]}{(Dxd7)} 31. Qxb5 {[%eval 286,29]}
{[%emt 0:01:00]} 31... axb5 {[%eval 172,27]} 32. Rd5 {[%eval 298,31]}{[%emt
0:02:11]}{(Sg4)} 32... Bxe3 {[%eval 182,27]}{[%emt 0:03:04]}{(Tc8)} 33. fxe3
{[%eval 278,12]} 33... b4 {[%eval 188,29]}{[%emt 0:02:17]} 34. Rb5 {[%eval
359,32]} 34... Ra8 {[%eval 186,30]}{[%emt 0:02:46]} 35. Rxb4 {[%eval 387,33]}
35... Rxa2 {[%eval 186,28]}{[%emt 0:00:11]} 36. Kf2 {[%eval 395,33]}{[%emt
0:00:42]} 36... Kh7 {[%eval 186,28]}{[%emt 0:02:37]} 37. e4 {[%eval 404,32]}
{[%emt 0:00:01]}{(Tb6)} 37... g5 {[%eval 187,24]}{[%emt 0:00:45]}{(Kg6)} 38.
Ke3 {[%eval 387,31]}{[%emt 0:02:06]}{(h4)} 38... Ra1 {[%eval 190,26]}{[%emt
0:00:52]} 39. Rb7+ {[%eval 476,31]}{[%emt 0:00:25]} 39... Kg6 {[%eval 185,26]}
{[%emt 0:00:27]} 40. Rb6+ {[%eval 505,32]}{[%emt 0:01:36]} 40... Kg7 {[%eval
222,26]} 41. b4 {[%eval 525,31]}{[%emt 0:01:39]} 41... Ra2 {[%eval 235,26]}
{[%emt 0:00:43]}{(Tb1)} 42. e5 {[%eval 723,31]}{[%emt 0:02:52]}{(b5)} 42...
Rxh2 {[%eval 276,23]}{[%emt 0:00:50]}{(Tb2)} 43. b5 {[%eval 1111,30]}{[%emt
0:03:35]} 43... Rh3 {[%eval 304,26]}{[%emt 0:02:55]} 44. Kf3 {[%eval 1819,31]}
{[%emt 0:01:26]}{(Tb7+)} 44... Rh1 {[%eval 337,24]}{[%emt 0:00:51]} 45. Rb7+
{[%eval 2056,30]}{[%emt 0:03:24]} 45... Kg6 {[%eval 366,26]} 46. b6 {[%eval
1931,29]}{[%emt 0:02:48]}{(Tb8)} 46... Kf5 {[%eval 414,25]}{[%emt 0:01:48]}
{(Tf1+)} 47. Rb8 {[%eval 2061,33]}{[%emt 0:03:30]} 47... Rb1 {[%eval 631,26]}
48. b7 {[%eval 2570,31]}{[%emt 0:03:04]} 48... Rb3+ {[%eval 647,29]} 49. Ke2
{[%eval 2654,28]}{[%emt 0:01:13]}{(Kf2)} 49... Kg4 {[%eval 658,29]}{[%emt
0:00:52]} 50. Kd2 {[%eval 2913,29]}{[%emt 0:00:47]}{(e6)} 50... Rb6 {[%eval
647,27]}{[%emt 0:01:03]} 51. Kc3 {[%eval 2941,29]}{[%emt 0:01:23]}{(e6)}
51... Kf5 {[%eval 687,23]}{[%emt 0:05:40]}{(Kxg3)} 52. Rf8+ {[%eval 9556,32]}
{[%emt 0:02:16]} 52... Kxe5 {[%eval 1731,25]}{[%emt 0:03:19]} 53. b8=Q+
{[%eval 32718,30]} 53... Rxb8 {[%eval 32722,29]}{[%emt 0:00:43]} 54. Rxb8
{[%eval 32724,34]} 54... Ke4 {[%eval 32732,32]}{[%emt 0:00:41]}{(Kf5)} 55.
Rh8 {[%eval 32734,37]}{[%emt 0:00:35]} 55... Kf5 {[%eval 32738,35]}{[%emt
0:00:16]}{(Ke5)} 56. Rxh6 {[%eval 32740,41]}{[%emt 0:00:48]} 56... Ke4
{[%eval 32742,43]} 57. Ra6 {[%eval 32742,44]}{[%emt 0:01:03]} 57... g4 {[%eval
32744,53]}{(Kf3)} 58. Re6+ {[%eval 32744,45]}{[%emt 0:00:39]} 58... Kd5
{[%eval 32746,64]}{(Kf3)} 59. Re3 {[%eval 32746,49]}{[%emt 0:00:33]}{(Te1)}
59... Kc5 {[%eval 32748,64]}{[%emt 0:00:01]}{(Kc6)} 60. Rd3 {[%eval 32748,55]}
{[%emt 0:00:29]} 60... Kb5 {[%eval 32750,64]} 61. Rd5+ {[%eval 32750,67]}
{[%emt 0:00:34]} 61... Kb6 {[%eval 32752,64]}{(Kc6)} 62. Kb4 {[%eval
32754,82]}{[%emt 0:00:27]} 62... Kc6 {[%eval 32754,64]} 63. Ka5 {[%eval
32756,94]}{[%emt 0:00:28]}{(Td1)} 63... Kxd5 {[%eval -32733,63]}{[%emt
0:00:56]}{(Kb7)} 64. Kb4 {[%eval -32735,0]} 64... Ke4 {[%eval -32735,1]} 65.
Kc3 {[%eval -32737,0]} 65... Kf3 {[%eval -32737,1]} 66. Kd2 {[%eval -32739,0]}
66... Kxg3 {[%eval -32739,1]} 67. Ke2 {[%eval -32741,0]} 67... Kh2 {[%eval
-32741,1]} 68. Ke3 {[%eval -32743,0]} 68... g3 {[%eval -32743,1]} 69. Kd3
{[%eval -32745,0]} 69... g2 {[%eval -32745,1]} 70. Kc4 {[%eval -32747,0]}
70... Kg3 {[%eval -32747,0]} 71. Kb3 {[%eval -32749,0]} 71... Kf4 {[%eval
-32749,0]} 72. Ka4 {[%eval -32751,0]} 72... Ke4 {[%eval -32751,0]} 73. Kb5
{[%eval -32753,1]} 73... Kd5 {[%eval -32753,0]} 74. Ka4 {[%eval -32755,0]}
74... g1=Q {[%eval -32755,0]} 75. Kb3 {[%eval -32757,1]} 75... Kd4 {[%eval
-32757,0]} 76. Kb2 {[%eval -32759,0]} 76... Kc4 {[%eval -32759,0]} 77. Kc2
{[%eval -32761,1]} 77... Qh2+ {[%eval -32761,0]} 78. Kb1 {[%eval -32763,0]}
78... Kb3 {[%eval -32763,0]} 79. Ka1 {[%eval -32765,0]} 79... Qg1# {[%eval
-32765,0]} 0-1