This is a per-sample thing. Due to manufacturing, some boards just simply do better with ram than others do, from what I've seen. If you look into this, you'll find reports of similar issues with other board makers, and at times, users simply needing to swap boards to bring stability where it wasn't possible before. That's the luck of the draw when overclocking.
It's also worth noting that certain BIOSes, no matter what board, are tuned for certain types of memory, and while board quality can help alleviate this, there is only so much possible while keeping things affordable. The "MemOK/GO_Button" is in place specifically to help with these issues, too.
