Replacing iTween.MoveUpdate with iTween.MoveTo

Hi guys, I am facing an unexpected problem with iTween. I am using MoveUpdate to move an object in two different directions at the same time, and it seems to me that something is going terribly wrong, since the object twitches on my iPhone, while FPS is > 40 (which means it's not caused by lag).

Now, I have found that this might be caused by iTween.MoveUpdate due to its nature, so I need your help figuring out how to replace it with iTween.MoveTo.

Here's the code I am using: http://pastebin.com/a7qfiFBG