So when I close my screen it'll go into sleep mode. Then when I open it up, it will have my cursor all messed up. I can't really explain it but it's like data matrix barcode or something. Then my computers really slow, when scrolling up and down a webpage it'll lag and whatnot. I'd restart the computer and everything would be working fine. It doesn't usually occur but it happens occasionally. Could it be a defective video card/mobo?