ODaM is quickly turning into my go-to place for D&D questions...I love how fast and thoroughly questions get answered here.
Now for my question: What happens when a character has two different forms of inherent DR? A Warforged Warlock could conceivably have DR of varying values, with one being keyed to Cold Iron, and the other, say, to Adamantine. Common sense would dictate that in a situation like this, they would both absorb their share of the damage before the DR is considered surpassed, but I could be way off with this. So, which is it?