I have a quetion. I have 1 stick of OCZ 512 DDR 400 and one stick Samsug of 512 DDR 400. why when I install both stick it only detect one stick of ram and not the other. I try one by one to make sure the ram work but when I install them both at the same time only one stick of memory work. And I have a OCZ 256 DDR 400 and I install whit my ocz 512 DDR and it detect 768 ram. but when I install the samsung it only detect one stick. Is it because that they are not the same type of memory.