I just upgraded my Asus UX31A to Win8.1 RTM and broke my Targus Docking Station (ACP71USZ). The USB ports work, but the monitors do not.
I get the USB device not recognized toast.
And Unknown USB Device (Set Address Failed)
I spent an hour with Targus and the WHQL guys to no avail.
Take my advice. Unplug your docking station while you upgrade to Windows 8.1.
I’m hoping Targus will send me a new dock.