My 2D physics worked perfectly in 4.3, but has not worked in any of the 4.5 versions. I recently found out the cause of the problem: some simple code that updates the Z position of my objects:
transform.position = new Vector3(
transform.position.x,
transform.position.y,
newZ
);
As long as I have this code and Interpolation enabled, my objects move about half as fast and stutter a bit. It doesn’t matter if I have the code at the beginning or end of Update(), FixedUpdate(), or LateUpdate(). Does anyone have an idea for how I might be able to work around this?