Shouldn't Favored Enemy count as a +1 enhancement against their DR? Last time I played a Ranger, it didn't seem to work that way.
I wish it was the case, but unfortunately not. It's +1 to damage every five levels, which is pretty nice in normal D&D settings but rather useless in Ravenloft due to the DR of most creatures.
Adding a DR overcoming attack bonus for favored enemies might be a nice addition, but it could be very unbalancing so I doubt it would happen (even though it would still be weaker than the monk ability due to the limited number of favored enemy types you can take).