K8T Neo FIS2R: network problems with FX5900 or WinTV

Hi folks

I am a newbie here. I am getting a problem with this mobo (a version 1.0
board). I run WinXP SP1 on a home network.

If I install WinTV usb, or install video capture on the MSI FX5900XT, my
network gets screwed up. Basically, another network is set up (why?) and
I lose dhcp and connections to all my networked drives. I can set up the
network manually, but can no longer access my network printer on I.E.

The video capture drivers for the card have several components. Problems
arise after I install one called "nVidia WDM A/V Crossbar"

It seems to me that WinTV (or the graphics card) has no reason to set up
another network. I suspect the mobo, or one of the chips. I have updated
to the latest BIOS (1.7) and to the latest Realtek Ethernet driver. What
has gone wrong?

--
Mike Austin