Very recently (last week perhaps) I've noticed that when I wake my macbook air from sleep sometimes I get a weird checkered horizontal lines pattern like the graphics have gone crazy. It only last for 2-3 secs (hence why I don't have a screen shot) before the computer wakes up and everything is back to normal. At first I thought it might be waking my computer when it was very cold (it is very cold in Boston right now) but I just had a much briefer but similar glitch when simply waking my computer from sleep after a few minutes while here at the office. These graphics glitches have thus far not impacted my ability to use the computer in anyway. It is more that I am concerned that there might be an issue with my motherboard. I'm running ML 10.8.5 btw and as far as I can tell I haven't made any major software changes during the time this problem cropped up. Has anyone else experienced anything like this? This is my work machine and one and only computer so I can't be without it for very long. But I was thinking of calling Apple and describing the problem to them. I bought this computer in late august so it is still under warranty but I'm not sure I'll be able to replicate the problem as it is so intermittent. Any advice much appreciated!