Itween Player Model Vibrates

Hey there!

Recently, I used Itween to help restrict player movement, the player runs around a set path and can only go back and forth. However, I found that when I start the game, the player model is stuck vibrating on the spot. Through various combinations of turning off other components and whatnot, I narrowed the problem down to the Itween script, more specifically the 'MoveCharacter' section, but I can't figure it out.

 using UnityEngine;
 using System.Collections;
 
 public class ItweenController : MonoBehaviour
 {
     public Transform[] controlPath;
     public Transform character;
     public enum Direction { Forward, Reverse };
 
     public float pathPosition = 0;
     public RaycastHit hit;
     public float speed = 0.5f;
     public float rayLength = 5;
     public Direction characterDirection;
     public Vector3 floorPosition;
     public float lookAheadAmount = .02f;
     public float ySpeed = 0;
     public float gravity = .5f;
     public float jumpForce = .12f;
     public uint jumpState = 0; //0=grounded 1=jumping
 
     void OnDrawGizmos()
     {
         iTween.DrawPath(controlPath, Color.blue);
     }
 
 
     void Start()
     {
         foreach (Transform child in character)
         {
             child.gameObject.layer = 2;
         }
     }
 
 
     void Update()
     {
         DetectKeys();
         FindFloorAndRotation();
         MoveCharacter();
         //MoveCamera();
     }
 
 
 
     void DetectKeys()
     {
         //forward path movement:
         if (Input.GetKeyDown("right"))
         {
             characterDirection = Direction.Forward;
         }
         if (Input.GetKey("right"))
         {
             pathPosition += Time.deltaTime * speed;
         }
 
         //reverse path movement:
         if (Input.GetKeyDown("left"))
         {
             characterDirection = Direction.Forward;
         }
         if (Input.GetKey("left"))
         {
             float temp = pathPosition - (Time.deltaTime * speed);
             if (temp < 0)
             {
                 pathPosition = 1;
             }
             else
             {
                 pathPosition -= (Time.deltaTime * speed);
             }
         }
 
         //jump:
         if (Input.GetKeyDown("space") && jumpState==0) {
             ySpeed-=jumpForce;
             jumpState=1;
         }
     }
 
 
     void FindFloorAndRotation()
     {
         float pathPercent = pathPosition % 1;
         Vector3 coordinateOnPath = iTween.PointOnPath(controlPath, pathPercent);
         Vector3 lookTarget;
 
         //calculate look data if we aren't going to be looking beyond the extents of the path:
         if (pathPercent - lookAheadAmount >= 0 && pathPercent + lookAheadAmount <= 1)
         {
 
             //leading or trailing point so we can have something to look at:
             if (characterDirection == Direction.Forward)
             {
                 lookTarget = iTween.PointOnPath(controlPath, pathPercent + lookAheadAmount);
             }
             else
             {
                 lookTarget = iTween.PointOnPath(controlPath, pathPercent - lookAheadAmount);
             }
 
             //look:
             character.LookAt(lookTarget);
 
             //nullify all rotations but y since we just want to look where we are going:
             float yRot = character.eulerAngles.y;
             character.eulerAngles = new Vector3(0, yRot, 0);
         }
 
         if (Physics.Raycast(coordinateOnPath, -Vector3.up, out hit, rayLength))
         {
             Debug.DrawRay(coordinateOnPath, -Vector3.up * hit.distance);
             floorPosition = hit.point;
         }
     }
 
 
     void MoveCharacter()
     {
         //add gravity:
         ySpeed += gravity * Time.deltaTime;
 
         //apply gravity:
         character.position = new Vector3(floorPosition.x, character.position.y - ySpeed, floorPosition.z);
 
         //floor checking:
         if (character.position.y < floorPosition.y)
         {
             ySpeed = 0;
             jumpState = 0;
             character.position = new Vector3(floorPosition.x, floorPosition.y, floorPosition.z);
         }
     }
 
 
     void MoveCamera()
     {
         iTween.MoveUpdate(Camera.main.gameObject, new Vector3(character.position.x, 2.7f, character.position.z - 5f), .9f);
     }
 }