camera slides and bounces while moving C#

I am using a mouselook script to control the camera. I use another script to “walk” the camera front and back but if i walk when the camera is not centered it still slides along the floor. I am not using a player script or tag and really dont want to. any suggestions to keep cam from sliding? I was thinking of making camera view snap back to center, but everything i do stops the whole script from working right.

Camera is rigidbody with box collider, set to use wood physic material. (script dont work without phys mat)

using UnityEngine;
using System.Collections;

/// MouseLook rotates the transform based on the mouse delta.
/// Minimum and Maximum values can be used to constrain the possible rotation

/// To make an FPS style character:
/// - Create a capsule.
/// - Add the MouseLook script to the capsule.
///   -> Set the mouse look to use LookX. (You want to only turn character but not tilt it)
/// - Add FPSInputController script to the capsule
///   -> A CharacterMotor and a CharacterController component will be automatically added.

/// - Create a camera. Make the camera a child of the capsule. Reset it's transform.
/// - Add a MouseLook script to the camera.
///   -> Set the mouse look to use LookY. (You want the camera to tilt up and down like a head. The character already turns.)
[AddComponentMenu("Camera-Control/Mouse Look")]
public class MouseLook : MonoBehaviour {

	public enum RotationAxes { MouseXAndY = 0, MouseX = 1, MouseY = 2 }
	public RotationAxes axes = RotationAxes.MouseXAndY;
	public float sensitivityX = 15F;
	public float sensitivityY = 15F;

	public float minimumX = -360F;
	public float maximumX = 360F;

	public float minimumY = -60F;
	public float maximumY = 60F;

	float rotationY = 0F;

	void Update ()
	{
		if(Input.GetButton ("Fire1")){
		if (axes == RotationAxes.MouseXAndY)
		{
			float rotationX = transform.localEulerAngles.y + Input.GetAxis("Mouse X") * sensitivityX;
			
			rotationY += Input.GetAxis("Mouse Y") * sensitivityY;
			rotationY = Mathf.Clamp (rotationY, minimumY, maximumY);
			
			transform.localEulerAngles = new Vector3(-rotationY, rotationX, 0);
		}
		else if (axes == RotationAxes.MouseX)
		{
			transform.Rotate(0, Input.GetAxis("Mouse X") * sensitivityX, 0);
		}
		else
		{
			rotationY += Input.GetAxis("Mouse Y") * sensitivityY;
			rotationY = Mathf.Clamp (rotationY, minimumY, maximumY);
			
			transform.localEulerAngles = new Vector3(-rotationY, transform.localEulerAngles.y, 0);
		}
	}
}
	
	void Start ()
	{
		// Make the rigid body not change rotation
		if (rigidbody)
			rigidbody.freezeRotation = true;
	}
}

Gui upbutton using NGUI for buttons.

using UnityEngine;
using System.Collections;

public class upbtn : MonoBehaviour {

    private bool isDownState;
	private float upspd = 0.2f;


    void OnPress(bool isDown)

    {

        isDownState = isDown;

    }

    void Update()

    {

        if (isDownState)

        {
 
		Camera.main.transform.Translate(0,0,upspd);
       }

   }

}

While i haven’t fully solved the problem, i did manage a bit of a fix for my specific game.
I just changed the minimumY to a lower value to restrict looking up or down too far.