Hi if you are using two sticks of RAM they should be placed in either DDR3_1 & DDR3_2 or into slots DDR3_3 & DDR3_4
Have you checked that your memory is supported by this motherboard? Is it on the QV list?
If possible could you post a few more details as to the components that you are using, Motherboard revision number, CPU, RAM (type and manufacturer), GPU etc., as this will all help if you are still having issues.