Media Center Extender network selection
How does the Media Center Extender choose between a wired and wireless network?
If when you bring the device out of standby it finds a wired link it will use it. If it doesn’t it will load the preferred wireless network. Thereby favouring the wired link.
However if you’re connected wirelessly and plug in a wired link it will continue to use the wireless until you come out of standby again at which point it will switch to the wired one.