Well. I hate to mention the mundane things, but I got to:
-Is the stick of RAM firmly in?
-Did you make sure you get compatible RAM? (Check Corsair.com for compatibility lists)
-Try the sticks on a different PC
-Try only 1 stick
-Try the other stick
-If 1 stick works, do Memtest86 on it (do the same with the other stick).
-TPG