My screen has been unstable the last few days, with the screen having variations in light (like flickering on and off but the screen is still there), then the screen starting to "curl" on the sides, so it'll go in half a cm on both sides for a few seconds, then bounce back to full screen, and, just now, my screen got warped--twice--so that it was a third of the full screen size! (but the full screen image is still there--it's just been shrunk!). What should I do about this? Could it be an overheating problem, and if so, how long should I leave it off for?