Try this:
The 1394 bus driver that is included with Windows 7 replaces the 1394 bus drivers that were included with earlier versions of Windows. See this site for details
http://www.microsoft.com/whdc/connect/1394_Windows7.mspx
You can try the following steps to fix our issue, This solved my initial problems with a Maxtor III OneTouch drive.
1- Click the Start Button, type devmgmt.msc in the “Start Search” box and press Enter.2- Expand the "IEEE 1394 Bus Host Controllers" node in the device tree on the right hand pane
3- Right click the host controller node select "Update driver software ..."
4- Select "Browse my computer for driver software"
5- Select "let me pick from a list of device driver on my computer ..." and Check the box before “Show compatible hardware”.
- 6. Choose the second option---1394 OHCI Compliant Host Controller (Legacy), and click next to update the driver.
I hope this can help you.
from here: