I have the original Pro2 and I used to get those green vertical lines that ran across the top of the screen.. When I first got them, the whole computer would lock up.. Then after I started getting them now and then, nothing froze and I was able to continue whatever I was doing (i.e. dragging a window over the green lines would make them disappear). Now that I've reformatted and stuck in another HD, I haven't had the green line problem once. I also don't get any blue screens, either.