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;
}