This is how I got my matrix to work with my v1.1
Below are instructions, if they are unclear let me know.
1) Solder very thin piece of wire (I used CAT5 cable) to the d0 point on the board (be very careful, it isn't as hard as it looks though). Solder the other end of the wire to a switch, then take a piece of wire from the other terminal on the switch to one of the xbox mother board screws. This will earth the d0 and tell the xbox to search for a BIOs at the lpc.
2) Solder a piece of thin wire to each of the points on top of the pogo pins on the matrix - ie: do not solder to the pogo pins but direct to the matrix. You do not need the d0 pogo pin on the matrix so don't solder anything to that.
3) Solder each of the wires to the corresponding point on the LPC, I filled the holes on the lpc with solder first, then heated the solder and pushed the wire through the hole to make sure it was a really good joint.
4) One all these points are soldered in your matrix should work perfectly, mine did! Remember when you flick the switch the d0 will no longer be earthed and the xbox will uses its original bios!!