It is not because of the pins (though it could be a bad cable). It is most likely a sequencing issue. Sometimes you have to hook things up in a particular order for it to work with Firewire. I don't remember off hand what the proper order is, but try to connect the camera while the power (of the camera) is off then turn on the camera. If that doesn't work try to have the camera on and plug the cable into the computer first and then the camera. Play with some other sequences as it should work.
If it still doesn't try to borrow a friend's so you can verify if the cable is bad. If your friend's works then it may be that your camera is not supported. make sure you have all the altest updates and then consult Apple. Hope that helps.