I don’t think it’s a hardware issues. I think that is a grounding issues. That happens to me occasionally but only when I charge the tablet and use it while I am touching the charger’s cable. When it charge, I does feel some small static electricity on the back cover. Since the touchscreen has electromagnetic as well (wacom panel works by an electromagnetic field) so I think itĀ gives an influence. I have seen some similar problem on I7 stylus as well on YouTube.