I am finding it hard to comprehend your setup, is two ram slots directly under your HDD? i don't see how that's even possible.
I bought a new ram and put in one of the 4 slots. ( the outside two. It does not work. I know the slot has damaged. The other two slots under the CD and hard drive, I lift up a quarter inch, move the old one in and place the other old one in right next to it. It works. Now it showed 4G on property. I can return the one I bought. For sure the outside two slot is damaged.