Huh, interesting. I managed to do it successfully on my X201, but only after supplying power through the RasPi I was using to flash it (no power to the board,

Huh, interesting. I managed to do it successfully on my X201, but only after supplying power through the RasPi I was using to flash it (no power to the board, battery and clock battery disconnected, though I doubt the latter was necessary).