Absolute sure, that it's not one of the sticks? Check them one by one and make sure bios registers them with the right parameters. I had just to RMA a 4*8Gb pack, because one stick failed.
ok, so i turned off my comp and put one by one testing all the ram and they all work , but when i put one single ram on slot a1 or a2 none work the light on the mobo that says "dram led Mem ok!" red light comes up so im guessing the slots don't work? ;(