The problem is that you are running the memory clocks too high.
4x high density modules require a lower memory bus speed than 4x low density modules or 2x high density modules. The extra chips on each module put a much higher strain on the IMC.
AFAIK Phenom II chips are only validated to run 4x HD modules at 667 or 533. You may need to run them at 2.0v and looser than spec timings with a CPU-NB voltage boost and reduced CPU-NB clocks to get all 4 modules working at 800 if its even possible.
HP-UX. I came, I saw, I was sad it would not run on my X86 box. [Official]AMD RX 480/ 470/ 460 Owners Club