Animating a fly through that ends rotating around something

I'm having a lot of trouble animating something that shouldn't be this hard. I have a camera fly through on the level within a circular room. Near the end I just want it to rotate around a specific point while focusing on it and then going to its final position.

I moved the camera around the object making the right keyframes and rotated to focus on the object. When I play it though the camera wobbles between keyframes even if it's a simple linear distance between the key values. Or sometimes it just randomly rotates in strange ways.

For instance between two keyframes, the z-rotation is 0 on both keyframes. But between the frames it animates up to 1.36 and back down to 0. Why?

Why is it doing all this and how can I get it to stop?