So recently my media program acquired a Macbook Pro (Newest Generation 17inch with Base processor, and 8GB of ram.)
We are using a Live Switching program called BoinxTv and we bought 3 Firewire Cameras to use with this program, Canon Vixia HV40's, we got all three to register and stream to the Macbook pro, Using 4 Pin (Camera Side) To Six pin adapters, and then adapting the firewire type (I think its 400 to 800, or the other way around) In order to get three firewire ports we bought a PCI express card that had two firewire inputs.
For some reason we can only get two of the firewire cameras to register on the macbook now, and its not one particular wire or camera we have swapped them continuously and the problem persists on a random camera. The one consistency is it would be running off the PCI express card. Once we take one of the canons off of the express card and plug in a standard definition off brand panasonic firewire camera all the feeds work fine.

Is their anyone who knows about this issue or how to solve it?