WD My Book 1TB Ethernet seems to hang my ...

When I map from Windows Vista drives to my WD MyBook 1TB White Lights disk with Ethernet port the USB ports on my PC malfunction. For example: My Logitech QuickCam Sphere AF doesn't work any more. The webcam doesn't reconize the USB connection anymore (noticable by the movements of the motorized cam under normal working conditions) and no cam image is shown software or within Live Messenger. When I try to power down i get the 'Shutting Down'' window for something like 10 or 20 minutes. Then Vista shows a bluescreen with a ''power state failure'' error message. Removing the drive maps in Vista to the WD drive won't solve the problem. When I additionally disconnect physically the WD drive from my network by disconnecting the Ethernet port and I reboot all problems are solved: the webcam works again and ''Vista shutdown'' works normal again. Seems like a WD driver for Vista driver problem. Can anybody help?

I am running a Lenovo T61 notebook with Vista Business Edition on a Wifi network. I purchased a WD MyBook 1TB White Lights disk with Ethernet connection.
Model: WDH1NC10000. Connected the WD with the Ethernet port to my router (AVM Fritzbox supplied by my Internet provider). Used DHCP to obtain IP address. Drive is reconized within Vista. I see the drive 2 times in the Network browser within Vista: 1 launches the Web based management application and the other one starts Media Player and plays music. The WD drive works fine but it seems to corrupt the normal function of the USB ports and it preveents my notebook to Shutdown normally.