Any reason why suddently these horizontal lines would show up on dark gray-ish backgrounds on my 2 months old TV? The model is UE55NU7402. Maybe the 1202 firmware update..? I'm fairly sure I didn't have it before because I tested gray uniformity thoroughly when I got the TV. It's annoying as hell while gaming. Factory reset didn't help. Please tell me as a last resort Samsung warranty will cover this otherwise I'll go nuts. The lines are perfectly symmetrical and have relatively clean edges therefore I wouldn't think it's a backlight issue whatsoever. (it's edge-lit anyway) Any help would be appreciated.