Another Gravity Question: Player suddenly flies upward

Edit: A new script was created to replace the Third Person controller, based off of the original controller. The player is not moving...

Edit: I found something out using the Lerpz Third Person Controller... The floating happens only after collision with the enemy. I ended up starting a game, colliding with the enemy several times, and then having the player float upward with all movements!

Gravity is giving me problems! I have the main character ("Player") in my game. He normally does what he should do when I control him, but at random times, he quickly floats upward. He eventually falls back downward, but not after leaving the room I have made through the ceiling. I have attached the Character Controller (from Unity) and a custom script for controlling the player. The code for the script is as follows:

     //Set variables!    
 var runSpeed : float;    
 var gravity : float = 20;
 var addedGravity : float = 3;
   
 var rotateSpeed : float;    
 var speedSmoothing : float;
     
 private var moveDirection : Vector3 = Vector3.zero;   
 var verticalSpeed : float = 0;    
 var moveSpeed : float = 0;
    
 private var collisionFlags : CollisionFlags;    
 private var lockCameraTimer : float = 0;    
 private var movingBack : boolean = false;    
 private var isMoving : boolean = false;
     
 
 function Awake (){    
     moveDirection = transform.TransformDirection(Vector3.forward);    
 }
                  
 
 function UpdateSmoothedMovementDirection(){    
     var cameraTransform : Transform = Camera.main.transform;    
     var grounded = IsGrounded();                
     var forward = cameraTransform.TransformDirection(Vector3.forward);    
     forward.y = 0;    
     forward = forward.normalized;                
     var right : Vector3 = Vector3(forward.z,0,-forward.x);
             
     //Inputs    
     var v = Input.GetAxisRaw("Vertical");   
     var h = Input.GetAxisRaw("Horizontal");
            
     right = Vector3(forward.z, 0, -forward.x);    
     var left = -right;
             
     if(v< -0.2){    
         movingBack = true;   
     }   
     else{
           movingBack = false;    
     }
 
     var wasMoving : boolean = isMoving;    
     isMoving = Mathf.Abs(h) > 0.1 || Mathf.Abs(v)>0.1;
    
     var targetDirection = h * right + v * left;
    
     if(grounded){  
         if (isMoving != wasMoving)   
             lockCameraTimer += Time.deltaTime;
    
         if (targetDirection != Vector3.zero){   
             moveDirection = Vector3.RotateTowards(moveDirection, targetDirection, rotateSpeed * Mathf.Deg2Rad * Time.deltaTime, 1000);  
             moveDirection = moveDirection.normalized;   
         }   
             var curSmooth = speedSmoothing * Time.deltaTime;    
             var targetSpeed = Mathf.Min(targetDirection.magnitude, 1.0);                   
             moveSpeed = Mathf.Lerp(moveSpeed, targetSpeed, curSmooth);    
     }        
 }
    
 function Update(){
 
     //create variable for the controller  
     var controller : CharacterController;   
     controller = GetComponent(CharacterController);
 
    //I know what to do here! Gravity!    
     moveDirection[1] -= gravity * Time.deltaTime;
   
     UpdateSmoothedMovementDirection();    
 
     var movement = moveDirection * moveSpeed; 
     movement *= Time.deltaTime;
    
     collisionFlags = controller.Move(movement);
    
     if(IsGrounded()){ 
             transform.rotation = Quaternion.LookRotation(moveDirection);  
     } 
     else{
       moveDirection[1] -= gravity * Time.deltaTime * addedGravity;
     }
 }   
     
 function GetSpeed () { 
     return moveSpeed;
 }
    
 function IsGrounded () {
     return (collisionFlags & CollisionFlags.CollidedBelow) != 0;    
 }    
 
 function GetDirection () {    
     return moveDirection;    
 }    
 
 function IsMovingBackwards () {    
     return movingBack;    
 }
 
 function GetLockCameraTimer (){    
     return lockCameraTimer;   
 }   
 
 function IsMoving ()  : boolean {    
     return Mathf.Abs(Input.GetAxisRaw("Vertical")) + Mathf.Abs(Input.GetAxisRaw("Horizontal")) > 0.5;   
 }
  
 function Reset (){    
     gameObject.tag = "Player";    
 }
   
 @script RequireComponent(CharacterController)    
 @script AddComponentMenu("Third Person Player/Main M Controller")

Does anyone have any suggestions on fixing this?

Edit: Here is the Player Damage script, which contains a collision event with the enemy. private var canDamage : boolean = true;

public var invincibletime : float = 2.9;

function OnTriggerEnter(Enemy : Collider) { if(Enemy.gameObject.tag == "MarshmellowMan")

{

 if(canDamage)

 {
    ApplyDamage();

 }

 else

 {

    return;

 }

} }

 function ApplyDamage() {
 
 
 PlayerStat.health -= 1;
 
 canDamage = false;
 yield WaitForSeconds(invincibletime);
 
 canDamage = true;
 }