Must Connect PWM cable in reverse for victor to work?

[Leav]

We connected our cables as per the instructions: Black side to black side on the Victor, and to the black side on the Robot Controller.

it didnt work. the victor flashed orange. (no PWM signal)

we checked everything, and verified the existance of a PWM signal with a servo.

after about 15 minutes Gal Longin (a teammate) had an idea which at first seems quite stupid: reverse the cables on both sides:
white cable goes to black terminal on victor, and white cable goes to black terminal on the controller.

it worked!

logic dictates that if you changed both sides, it should be the same.

after another 5 min we checked cables that we got with the RoboVision kit, they worked with the normal black to black setting....

how can this be???

-Leav