At work we just bought two Samsung S27A950D screens. They allow both DisplayPort, HDMI and DVI connection. We also bought mini-DP -> DP cables. When conneting these to our 13" Macbook Pros (2.3 GHz), there is no picture on the display. Neither screen, neither cable, neither computer. The laptop screen does the blue blink once when connecting the cable (so something happens), but no picture on the Samsung and no screen detected in the Display settings. If I connect the screen via DVI and DVI -> mini-DP adapter, it all works perfectly. This, however, is a bit bulky, so I would prefer the smaller DP cable instead. At this point I gave up and just went with DVI. Strangely, however, I later noticed that when I connected a slightly older 15" MBP (2009, 2010?) it worked perfectly with the DP cable. What the...? What is going on here? Problem with Thunderbolt vs DisplayPort? Problem with the Sandy Bridge graphics? This is really getting on my nerves. Any help or insight would be appreciated.