That is really strange. Do you have any open wires under your panel as the charge shouldn't carry through the plastic buttons, into the microswitches, and down to the encoder.
Does it always happen when you come back from being away, or just when you feel a static charge disipate? Have you tried starting it up and dragging your feet, with socks on, across the carpet, to create a small static charge? If this still causes it then something is very wrong, if not it could be some issue with delay or a screensaver.