Firewire bus problems: an apple kb article

The firewire bus has often been flaky on Apple's machines. Sometimes it stops working, sometimes it restarts under peculiar circumstances. I've always thought this was somehow related to Apple's complex hardware abstraction approach and the complexity of what firewire does (a sort of peer-to-peer mini-lan). Whatever the cause for this perennial problem, it's interesting to note that Firewire audio devices can create a problem that's solvable by an SMU reset on some machines (see link for how to do the SMU reset):

Power Mac G5 (Late 2005), iMac G5 (Ambient Light Sensor): FireWire bus stops responding after computer restarts with FireWire audio device attached

If a FireWire audio device is connected to a Power Mac G5 (Late 2005) or an iMac G5 (Ambient Light Sensor) while the computer is restarting, the FireWire bus will stop responding and no FireWire devices will be detected on the bus. The device may stop responding or stop charging, depending on the specifics of the device.