If you have to use defaults (F2) like you said then your rig is not overclocked. Sounds like your not saving your bios settings (F10) before you start up but rather using the F2 selection to get up and running. At least that's how I understand your post. Have you tried removing your new hardware and then reinstall one at a time or did you add them all at once? As of now it's a bit confusing to what might be the actual problem.