The problems is in the method BasicRobot#scrollIfNecessary(JComponent c, Point p) when we call method isPointInScreenBoundaries(c,p). This method returns true if the component is inside the screen dimensions(screen size). There are cases when the component is inside the screen size but is not visible(is inside a scroll pane). I added two files that reproduce the problem. In this example I try to click on a button that is not visible but is in a scroll pane. The resolution of my PC is 1440x900. After running the test you should see on your console printed "Clicked Button", but this doesn't happen.
I think the solution to this problem is to remove the check if the component is inside screen boundaries from method BasicRobot#scrollIfNecessary(JComponent c, Point p).