I have found my first Asrock board (Extreme 4, Gen3) to be fussy about RAM. First issue was swapping out a 2500k for a 2600k. It suddenly would only show RAM in two slots instead of all 4 and seemed stuck in single channel mode. This last time all I did was move to a different case and heat sink/fan. and I could not even POST. I got error 55 which is RAM. Removed all but one 4GB stick. After posting I added another stick. That was okay so I added back the other two. left the RAM & CPU on the board when moved it. I use Corsair RAM. Why these boards hiccup with RAM issues lead me to believe it's still a BIOS issue as we have different boards. I called Asrock and told them about this last week and to contact their engineers in Taiwan to fix the darn BIOS.

Mark, glad you got yours working but what a PITA.