In November I got the Retina iMac and I absolutely love it! Upgraded from a 2012 27" iMac and am glad I did. However, whenever I have my Belkin Thunderbolt 2 Dock plugged into the machine upon start-up, the Mac just sits there on a black screen (screen is on but is black) and will never actually start-up. Shut down, unplug dock, restart, and boom... machine starts up. Also, in relation to the Thunderbolt Dock: When it is plugged in while the Mac is running, the Mac fans run really loud about every 3 minutes. While it's happening, I try to look at Activity Monitor to find any intensive processes but there is nothing. I unplug the dock and the fan noise goes away. Is anyone also having these issues? It's pretty frustrating. Frustrating to the point where I have pre-ordered OWC's new Thunderbolt dock (which actually has more useful ports for me).