If you network two Macs over FireWire, such as using IP over FireWire, you may not be able to use other devices on that FireWire bus. This means that a connected iPod or iSight, for example, may not be recognized properly, or may even appear on another Mac computer that is part of your FireWire network.
To prevent this from happening, disconnect your other Macs from the FireWire network before using any FireWire devices that exhibit this issue. If you have a FireWire card installed (or an open PCI or PC card slot to install one), you can alternatively use it to connect the computers on a different FireWire bus from your FireWire devices (connect these to your computer's built-in FireWire ports.