Overvolting leads to no boot. Help plz.

So yeah, I'm still throwing up some clocks for my old 805 proc and I was wondering what is hindering my overclock. The ram isn't the best but the dividers put it in it's place. I had massive stability problems. The highest vcore I can set it too is like 1.4325v. Any higher and there is no boot. No screen, nothing. Is this like a bug or maybe psu issues or what? Anyone know? The vcore can be set to some crazy number since this is on a p5w Dh board with 1407 bios.... (i forget- 9/06) so it's recent. The same thing was happing on my p5Ld2-deluxe. I'm not curious about the FSB or overclocking- I can work that out slowly. Just wondering why I can't overvolt it past that point.

What are the specs on your PSU?
32+ 12V amps is a good place to start with that CPU.

check the V(core)droop at the Ghz your able to overclock to now.