I had a soyo motherboard that did the same thing after a bios fix.
The system would start, then restart itself and start normally after than.
I doubt its the hard drive. The hard drive is incapable of turning itself on or off.
Sure indeed. In fact, I guess all that mess has to do with:
A) the mobo bios (it's new and in continuous progress)
B) the sata controller drivers
C) the sata ports usage (there are six of them on the mobo)
Do you think one of these is right?