Most MB's on the market today run the ram channels through the CPU's, which can only run @ 1.5V and @1333 So when the bios receives info that there is a spd/Voltage of higher specs it believes that you/somebody is trying to overclock and attempts to compensate. This usually ends in an instability. To over come this, it takes some major moxy know-how and manipulation in the bios and sometimes even windows itself to get everything up and running stable. Even then, you may have to reset everything in the bios each time you restart.
For some this is fun and a constant exhilarating challenge. For others it's a major pain in the B. It depends on your point of view.
Dont i know it, I have read loads of articles even in the how to's on here how they got the same ram as mine working at 1600 on 1.65v and it wouldnt do it for me. Its taken nearly 5months for me to do it which i think is down to tghe new bios.