Hello everyone. Here’s an explanation from our CTO:
The issue in general is a problem with earth and the earth of the environment. There are many really bad switching power supplies out there these days which cause a lot of earth problems. Just very briefly, a switching power supply basically removes the reference ground from the output voltage. Between the GND and the DC pin of the output you will always have the correct voltage (in our case +19V DC) but there may be a substantial voltage (usually AC) between this GND and earth - this can be up to 120V but with almost no power so it is not dangerous, just uncomfortable when touching. Devices which operate with very low charges, like the touchpad, will get totally confused.
So if people e.g. have a cheap LED light on their desk and the desk is slightly conductive this can already cause a voltage difference between the GND of the laptop and the desk resulting in voltage and current flow when touching the touchpad.
Our latest chargers should be good. We used to ship, over a year ago, chargers that had a significant voltage from GND to earth. But we’ve discovered a potential problem, so the current chargers that we ship should be okay.
Apart from that you could / should check your environment for other potential GND-earth problems. If the table has a metal frame I would even suggest earthing the table’s frame. This is a common problem and since we use a metal case (like many others too) the case is connected to DC GND and thus prone to such problems - like any other metal case device too. (Sometimes just standing with your feet on an AC cable can be enough to cause such problems too…)