switching scene, first one stops to work properly

Hi im new to unity (and programming!). i got a anoying problem and i would really need some help.
When i first start the menu scene, everything works properly, then i go to another scene and work there, when i go back to start the first scene(menu) the gui button are invicible. This i know because i can still press it because i remember where it were

Those are the scripts
script 1, used for the menu buttons:
using UnityEngine;
using System.Collections;

public class Start : MonoBehaviour {
	bool showBox = false;
	// Use this for initialization
	void Start1 () {
	
	}
	
	// Update is called once per frame
	void Update () {
	
	}

	void OnGUI(){

			
		if (GUI.Button (new Rect (Screen.width / 2 - 50, Screen.height / 2 - 200, 200, 75), "<size=40>Start</size>")) {
			showBox = true;
						
				}
		if (showBox) {
			GUI.Box (new Rect (0, 0, 100, 25), "Loading...");
			Application.LoadLevel ("något");
				}
		}

		   
	}

script 2, used for background image: 

using UnityEngine;
using System.Collections;

public class BackgroundMeny : MonoBehaviour {

	public Texture2D BackgroundMenu;
	// Use this for initialization
	void Start () {
	
	}
	
	// Update is called once per frame
	void Update () {
	
	}
	void OnGUI()
	{
		GUI.DrawTexture(new Rect(0, 0, Screen.width , Screen.height  ), BackgroundMenu, ScaleMode.StretchToFill, true, 10.0F);

	}

}

so currently i have to make a new button script everytime for my menu to work. is this a bug or what? All help would be appreciated

Boy I have the perfect script for you,

var ButtonID : int = 0;

// ID of 1 = Quit button.
// ID of 2 = Sceneloading button
// ID of 3 = Unhides an object
// ID of 4 = hides and object
// ID of 5 = turns off parent, while turning on target(useful for switching between tabs)

var ID2_Scene : String;
var ID_object : GameObject;

var ID5_target : GameObject;

function OnMouseDown(){

	if(ButtonID == 1){
	Application.Quit();
	}
		if(ButtonID == 2){
		Application.LoadLevel(ID2_Scene);
		}
			if(ButtonID == 3){
			ID_object.SetActive(true);
			}
				if(ButtonID == 4){
				ID_object.SetActive(false);
				}
					if(ButtonID == 5){
					gameObject.SetActive(false);
					ID5_target.SetActive(true);
					}
}

if it’s a quit button, enter ‘1’ into ButtonID, and leave the rest alone.

if the button loads a scene, enter ‘2’ into ButtonID, and put the nameof your level into “ID2_Scene”

and so on and so on.