Maybe I'm just doing this one wrong. I thought the black squares weren't allowed to be part of the puzzle pieces, though. Is it possible for someone to check the solution?
I've checked the solution for you. It appears that the black square in the sixth row is part of the pieces. The rules refer to "completely black squares". You can see an example of these completely black squares in puzzle 1136: http://www.puzzlepicnic.com/puzzle?1136
How much wood could a woodchuck chuck if a woodchuck could chuck wood?