iTween Orient to Path Jumping Between Nodes

I have a cube which I got to follow a path using ITween path. This worked great, but on trying to use orienttopath to get the cube to face the direction it was going, I ran into a problem.

On implementing orienttopath, the animation is now choppy. The box will move to the start of the path, as planned, then it will stop, rotate at whatever speed I set (according to looktime) and once it's done rotating to face the next node, it will teleport there, and rotate to the next point, etc. An interesting point to mention is that on setting the speed of the box higher, it appears to lerp between the points a little, still appearing choppy and stopping at each node, but clearly moving between them, rather than just teleporting.

Side note: I'm not sure about this because it's hard to tell, and it's secondary to the main issue, but it appears that orienttopath only orients the box to face the next node, rather than the direction of the curve of the

iTween.MoveTo(gameObject, iTween.Hash("path", iTweenPath.GetPath("Tracks"), "speed", speed, "looktime", 0.5f, "orienttopath", true));