This issue occurs because the 1394 bus driver in Windows 7 does not issue an Open Host Controller Interface (OHCI) Soft Reset command to the 1394 host controller. This occurs when the computer sets the device to a low power (D3) state. When the computer sets the 1394 host controller to a high power (D0) state, the host controller may generate an incorrect PCI-Express packet. In this situation, the motherboard chipset stops responding.
Note In Windows Vista and in earlier versions of Windows, the 1394 bus driver issues an OHCI Soft Reset command to the 1394 host controller when the computer sets devices to a low power (D3) state.