It seems this one was a bit of a stumper, but I have six solvers to announce. In chronological order: avenger314 (who hadn't finished first since Puzzle 1), Stanza, Tahnan, GLmathgrant, moussambani, and groza528. I've offered a prize to Karl Voelker for catching the error in my instructions! I also offered one to avenger314. Send in your comments and answers - you never know when I'll offer a prize, or what it'll be.

On deck: two rising stars in the puzzle world - one relatively recent invention that's sweeping Japan, and one old classic that is presently drafting behind Sudoku. - ZM