is the RAM designed to work @ 1.5V but can stand up to 1.9V or does it need 1.9V to run reliably ? With the ASUS should be able to bump the voltage to 1.9V whereas big box, off-the-shelf PCs don't usually have those voltage options in the BIOS. On the downside...higher voltage means greater heat.

Bottomline, I'd ask Kingston and see what they say. Please let us know too.