I have got my white macbook last week. Everything is fine other then I have noticed something wrong with the display. At the top of the display screen, I can see grainy lines. I can't see these lines at the bottom. Does anyone know of these lines? It's like the quality of the top of the screen is poor and grainy and the bottom half is OK. Does anybody know how to get rid of them? I tried securing virtual memory but still shows. What do you reckon the genius bar staff will say if I took it to them?