Whenever I"m in a house, or ESPECIALLY Dawnguard keep, the framerate becomes jumpy, and not smooth and fluid. I'm not talking about screen tearing or slowed framerate, but I'm talking jumpy. I've figured it out though. I believe it's the "friendly auto aim". If I'm in fort Dawnguard where as the room is empty of people, my camera stays smooth and fluid. However if someone enters that room, once upon looking at them or in their direction, my camera jumps, like auto aim is messing with me. I really urge you to try this so you can see this for yourself. This is also bad in Soul Cairn, and I'm not sure why.