I have a problem where the page down button often doesn't work (seemingly at random), but as soon as I move the mouse, the screen immediately jumps down. If I've pressed page down twice, it will go down two screens, so it's like it's stuck waiting for something; but nothing is loading, it always goes at the instant the pointer moves. Just waiting doesn't do anything. There appear to have been some other issues with page down not working at all, but I haven't seen anyone else with this, and it's pretty irritating...