The issue is the grounding for the charger. I tested this myself with an asus Q200e. I lost the OEM charger and had to purchase another one. Once I began using the aftermarket charger, the erratic behavior began. The only saving grace is that the laptop is a metal body. So If I place my palms on the body and use the touchscreen or pad, the erratic behavior stopped. As soon as I removed my hands, it began again. You'll need to purchase a charger that is internally grounded or has a ground loop isolator built in. Otherwise, you'll have to find a way to ground the laptop while using the charger.