I had the same issue with height and it wasn't in any of the upgrades, it was in new but bad blades. I would pull off all the blades and make sure they are good blades [link]http://www.youtube.com/watch?v=_7PwNTXOWMs[/link] if they are bad then try this [link]http://www.youtube.com/watch?v=RmNv8OlG6GQ&feature=related[/link] hope it helps but also it could be that the outer shaft collar is on too tight it needs about 1 paper width of play from what I hear