A user called phairou did raise the same issue a few days ago over in the Arduino forums, same pictures etc. Although the documention requested on the shield pinouts was apprently not available at the time.
The documentation linked in this series of posts suggests the shield uses pins 13,12,11 for SPI, which wont work on a Mega 2560.
J8 appears to be the SPI\ISP connector which is what the shield should really be using to pickup the appropriate SPI connections.