Did you multiplier overclock only or did you move the ref.clock up any? If you moved the ref. clock up it could very well be your memory causing the instability. If you used multiplier overclocking, the memory should be at the speeds you set it at. Have you tried setting the cpu back to stock and running those tests to see if it is in fact your memory. Many people have had some trouble getting their RAM up to 1600 on AMD systems, because on AMD systems it is considered an OC, try 1333 and see what happens.