JCheckBox as part of the compound JTree node unpredictably responds to the mouse click. When JCheckBox being clicked, it randomly produces Mouse_Pressed event instead of Item event, or generates Item event as it should. In case of Mouse_Pressed, the box stays OFF but get highlighted. In case of Item event, it simply turns the button ON as it supposed to. JTree has both TreeCellRenderer and TreeCellEditor set up to display and edit compound node.