It does sound like it could be on the way out, could the bios have become corrupt somehow? im sure you tried both bios's on the board. my dmm readings look ok btw.
so maybe you need to rma that board?

I dont know about where you live but here in the uk, Asus rmas take forever [6-8 weeks!] I always hope I can get the retailer to swap my boards if possible. the Asus direct process really sucks here.