I found this in a few different places around the 'net - hopefully it's helpful:
Stop Jerky Graphics
If you are connected to a LAN and have problems with jerky graphics, this might be the solution:
- Right-click "My Computer".
- Select "Manage".
- Click on "Device Manager".
- Double-click on your NIC under "Network Adapters".
- In the new window, select the "Advanced" tab.
- Select "Connection Type" and manually set the value of your NIC. (Not "Auto Sense" which is default.).
- You should reboot.