I may just try jumpering to the isp but i'd rather look at the schematic first.
That is always a good idea, but some can be deduced by the setup. If the shield works when connected, and doesn't when jumpered, then it is not jumpered correctly.
I note that it has an ISP female header that plugs into the arduino male and i'm wondering if that is where it is getting its spi signals.
Jumper the six ISP pins to the ICSP pins on the Arduino. I can see the traces on the ISP connector to the pads labelled MISO, MOSI, and SCK. That is how the newer shields that use SPI connect to the SPI data lines. Then it will work on a Mega too.
edit: Maybe it is my eyes, but I bet if you look closely at the pads labelled MISO, MOSI, and SCK, that there is a small thin jumper trace between the center pad and the right pad of the three, but not from the left pad to the center pad. To me, that would indicate that this shield is using the ICSP pins for the SPI, and D11-D13 are not used.