Use of Arduino Motor Shield R3 without stacking on Arduino

Due to some pin conflicts I need to alter the pins that the "official" motor shield from Arduino uses. It seems that the simplest way to do this would be to un-stack the shield from the Arduino and wire the pins header-to-header.

However when I did this I found the shield to be non-functional. (When stacked on the Arduino it was able to run the motors fine using a test sketch.) Besides the direction, brake, pwm, etc pins, are there other pins I need to connect from the Arduino to the shield (maybe a vref or vcc or ground?) in order to get it to work?

Yes I'm 100% sure but believe the PWM requires Vref and GND.

Lubby, thanks for the help. I got it working tonight with just pulling over the 5V line and GND from the power pins, in addition to the pwm and direction pins (brake pins disabled). In order to work it needs the 5V and GND from the Arduino in addition to an external supply for the motors.