The reason I mentioned it is because I had a enermax galaxy psu that did a similar thing on a rampage extreme [x48]
anyway to cut a long story short, the psu was absolutely fine on any other board so essentially there was nothing wrong with it.
I called enermax, they said return it to them, they sent me another psu, a newer revision [same model] which worked perfectly and is incidently in my rig on this board [x58]

There was no sense in it and all the rails reported as they should. It may be that its not your psu, but I would say its either that or the board, if your ram is passing memtest
and voltages for the ram are set in bios, I dont see how ram can be contributing to your cold boot issue. its an odd one, and trying a different psu is a good idea even just if its to rule it out.