The only other suggestion I have is to review the DZ77GA-70k Performance Tuning Guide.
I used a memory that supports XMP profiles (1866 MHz) and the memory profile shows up in the BIOS Performance Memory Profiles - drop-down menu.
However there is a caution that using memory voltages over 1.5 may reduce processor life!
I've gone into the Visual BIOS and changed the memory profiles:
Advanced Setup > Performance > Memory > Performance Memory
I tried two profiles:
Profile 1: XMP-2400 - When I started in this profile, it gave me the following error message:
"BIOS has detected unsuccessful POST attempts. Possible causes include recent changes to BIOS performance options or recent changes."
When I try profile 2 (XMP-2133), the screen goes blank and I cannot see anything on screen. I cannot tell if anything has loaded - nor do I see the Intel startup screen (with F2/F7/F10 options).
BTW, I am also using Ubuntu 12.04 LTS. So I'm still wondering what I need to do.