Hi, I've installed OS X Lion DP 4 on my 2011 MBP today, not without any problems, but eventually it worked. But I've stumbled onto some issues. First of all gfxcardstatus doesn't work quite well, but the developer will probably resolve that issue, but the biggest issue for me is that Preview doesn't work for video's while it does work for mp3's. Something weird... I And everytime I boot I get a weird glitchy screen and every time I disconnect my secondary monitor (iMac) my background disappears, but I guess these are related to the AMD GPU. Has anyone had these same issues?