i think this is a psu problem, it only has enuff juice to power up some of your parts at once and on the 3rd try has all the caps full up and can initiate the cpu.
try unhooking the floppy, cd rom and pci cards and leave only 1 stick of ram , one hdd and the video card in.
if it starts then , then its a very good chance your psu is too weak.
let me know if this works.
Gigabyte 990XA-UD3/8 Gigs Corsair Vengengence CMZ8GX3M2A1
PHENOM II 4 CORE 955 Black Edition/Antec-Kuhler 920
KINGSTON64 GB SSD hdd
LG Litescribe sata BD/DVD/CD Burner
RADEON HD 6870, Dell 24" & Acer 23" monitors plus 42 plasma
ANTEC EarthPower 750W psu, Creative SB X-FI Extreme Music
Logitech 5500 spkrs