Sparkfun Shield with MEGA2560

Hi,

I have been trying to use the Sparkfun USB host shield on my Arduino MEGA2560.
Having done some research online, I understand that the shield does not work 'out of the box' when used with a MEGA2560, as it would with an UNO.

I have added jumper wires from pins 10-13 over to pins 50-53 on the MEGA.
52->13
50->12
51->11
53->10

I understnad that there is a solved case of this on this forum, but I cant seem to get my set up working.
My question is, do I only need to make a hardware modification?
( I have added the jumper wire from pin 7 to reset button, and am powering it via the Vin port).
It works perfectly with an UNO, so the only issue is the SPI communication.

I cant seem to find files like ' MAX3421_constants' and hence am unaware of any changes that need to be done on the library file. I have not made any modifications to my code either.
Anyway help would be greatly appreciated.