The first time you turn it on it's quite normal for it to power on, then off, then on again (mine does that everytime it has been switched off on the back of the PSU - there's a reason for it, but I can't for the life of me remember what it is).
Error code 99 "Super IO Initialization" is a bit of a tricky one to troubleshoot as people have many different issues (one example being having a 6 pin in the 8 pin EPS socket). Out of curiosity, what display are you trying to use? It's not unheard of for a TV that's being used as a display to cause this problem.
Does your CPU have integrated graphics? If yes, try removing the graphics card and plugging your display into one of the motherboards ports. This could at least help rule out the graphics card.
I'm not going to lie to you, this could be a tricky issue to fix (and possibility beyond my ability), so if you haven't already, you should probably make a post on the ROG forums about your issues. There are some real experts there on the particular oddities of the ROG motherboards. Here's a link to the VI motherboards section of their forums:
http://rog.asus.com/forum/forumdisplay.php?155-Maximus-VI-Motherboards If you search on there you'll find some others with similar issues as well.