i found another glitch. if the dock is quite large (many items, icons, tasks, systray) so it kind of reaches the screen side limits, it probably tries to selfadjust? the effect is that windows (reserved edge on for nexus) kind of shimmer on the lowest part. the dock seems to stay put but the hight of the screen reserved area varies, by 2-4 pixels. it sort of "blinks" the maximised running windows above the dock.