I was editing my video in Final Cut Pro X, then suddenly, a bunch of lines and blocks and shapes appeared on my screen (graphical glitches). This happened to me back in April this year, I turned the LCD smoothing off, and never had this problem again, until today. I first tried to just restart the computer and ignore the problem, but it came back. I highly suspect that this is still a problem in OS X Mavericks. Can anyone confirm this or tell me what is the problem? If it's a software issue, I will downgrade to Snow Leopard.