The only thing I can suggest is trying to run with one memory module, then the other module, and see if either provides more stability. For clarity sake, let's call one RAM 1 and the other RAM 2. You have two slots; call them slot 1 and slot 2.
Try RAM 1 in slot 1 with slot 2 empty. If that does not allow the system to work well, try RAM 1 in slot 2 with slot 1 empty. If that does not provide more stability, try RAM 2 in slot 1 with slot 2 empty. If that still is not stable, try RAM 2 in slot 2 with slot 1 empty. See if any configurations lead to a stable system.