I was playing SCUMMVM DS for a bit and decided it was time to take a break. After I shut it off, I noticed a weird little mark. Upon further inspection, it looks like the plastic screen is touching the LCD. I turned my DS Lite back on and and I noticed that when I move the lid it puts pressure on the screen where it's making contact. My guess it's the heat. It's pretty hot here in SoCal, but I don't think it's that hot for them to touch... Call Nintendo for a replacement?