Try BIOS P0H (BETA, but better than 1.3): http://www.box.net/shared/gsn4mgt6o4

Load defaults and then flash with parameters /p /b /n /c

Let me know if you get the same problem. It looks like memory to me.
Also check your PSU voltages on all rails at boot.

If you still get it, can you describe exactly what happens and at what stages?