Hi there, I'm having problems getting this combo to work with the monitor's display port set to 1.2, at 1.1 it works fine but 4k is limited to 30Hz. To get the 60Hz rate I switch to 1.2 but there's some flickering and after a few minutes the screen goes black, the monitor says there is no input and it goes to sleep. The same thing happens with a MacBook Pro and 1.2, even though the laptop can only do 30z. Is this thing a lemon or are there known issues using this display and a Mac Pro? I'm using the displayport to minidisplayport adapter.