When the screen is off (in powersave mode) but I accidentally move a little bit the table where the keyboard and mouse are, the screen is on again. I am of the opinion that the screen should only wake up from the powersave mode when the mouse is moved intentionally and not a little bit by accident. Probably with another control in KCM it will be possible to modify how the mouse behaves to wake up from powersave mode, for example defining the number of contiguous mouse events or the minimal distance.