Try high tRFC (89+) plus have you tried higher VTT and vDIMM? I mean, really higher.. I need 1.45V VTT and 1.75V vDIMM to run my specs (1600 CL8). Btw. I had G.Skill before it seriously bottlenecked my OC, before I released tRFC a lot. And even then, not that stable as I have it now. Maybe mobo doesn´t like anything except Hypers and Microns.