I agree, does sound like a power glitch of some sort. I understand Windows does a hack job reformatting SD cards, writing over some delicate table of some sort but I can't say I've ever run into problems reformatting them with windows, myself.
I had what one would call a bed micro sd card.If one rebooted the Roku the card would never let the Roku finish booting up. Take in the card out allowed the Roku to boot and work properly. To fix I just reformatted in the pc and reinserted it back into the Roku. No clue as to what went wrong. just know the fix.
Roku 2xs (3100x), Roku Express (3900x) ,Roku Ultra (4660RW) .FIOS Quantum modem router, Verizon FIOS 100/100, LG HDTV 42LH90, Pioneer VSX-920 Audio/Video Multi Channel Receiver