Hello, I am using dell xps m1330 from last two years. i am very happy with my laptop. from last 2 weeks or so , I am seeing a brown like patch on my screen. and few marks like thumb size in the middle. They are visible the most on the white background. It is like a burn colour or so. I have never had any problem with the screen now also its working fine except i can see this dark brown like a stain or so . i will really appreciate if someone can advise me here . thank you so much.