I meni se to desavalo s monitorom Dell U3415W kad je bio spojen preko DP porta ,ali sam nasao firmwire za monitor koji rjesava taj problem na Dellovim stranicama. This firmware upgrade package is for U3415W monitor. After the upgrade, the firmware will be M3B103". Fixes random screen flicker over Displayport". Updejtao firmwire i problem rijesen,nikad vise mi nije zacrnio.