After turning on those databases and making the improvements regarding material evaluation, I had to compute an entirely new book. It was obvious from the first match against Kallisto that my book was no good at all. I didn't have much time for this, so the book was small, only about 20'000 moves (I've forgotten the exact number!). After all my improvements, I incremented the version of Suicdal Cake to 1.13c. It scored a clear victory in a small test match against 1.11, but not a clean sweep like Kallisto had done. Therefore, I was not very optimistic about its chances against Kallisto (BTW, the official name is Kallisto Suicide Checkers 1.13, but that's too long to type all the time...).
The MatchMy fears about Suicidal Cake's playing strength were quickly confirmed when it lost the two first games of the match in a similar fashion as in the first match: in the first game, it grabbed material and lost quickly, and in the second game it was in a cramped position in an endgame and lost. In game 3 however, it sacrificed a man itself, and won convincingly while the final game was an uneventful draw. All in all this was a much better showing than in the first match, but SucicideKallisto still seems to be stronger.
If anybody reading this spots a general rule about suicide checkers that SC was violating and that SK understood, please tell me what it is by sending a mail to nospam1 at fierz dot ch - thanks! Of course, I'm trying to find out myself too, but any help is appreciated :-)