i have the same motherboard and the same thing happened at one point (but not it's screwed now, even made a thread about it)
i kept pressing the memok! button but it never fixed it, the dram would still be red, even when i restarted. i just redid everything, and it turns out that my gpu wasn't seated too firmly, so i fixed that, booted it up, dram led didnt flash and went on successfully. don't know what gpu has to do with the dram led but it worked for me.
Thanks! It worked for me after I reassembled my GPU and clean the RAM slots and place it again...its a bit weird but now RAM is running on 1333 instead of 1600 ...