OpenChess

Here's one that some of the stronger programs struggle with ( on my one core testing at least).
Sparc, Junior 11.1 and Rybka get this quickly while Toga, Komodo and Stockfish take awhile.

Also, does anyone know where this game comes from?

r2q1rk1/1b2bp1p/pp3np1/2pp4/3P4/1P1BP3/PBQ1NPPP/3R1RK1 b - - bm c4;