John,
I had exactly the same issue and I solved doing this:
I tried some configs on my BIOS and managed to boot with my 2 sticks of 8Gb each.
What I did was increase the memory voltage to 1.650 and increase the System Agent
Voltage to 1.000. After that, my two sticks of 8Gb worked fine!
Now I have 32Gb (4X8Gb) working ok!
I hope it works for you!