GUI Error: You are pushing more GUIClips than you are popping. Make sure they are balanced)

I have an error in my GUI script for my main menu. I get: GUI Error: You are pushing more GUIClips than you are popping. Make sure they are balanced)

I know what this error means as I've sat here googling it over and over again but yet all the solutions are the same. I must have as many "Ends" as there are "Begins" but that doesn't seem to be the problem as it is fine.

I also get the error: You can only call GUI functions from inside OnGUI. However this does not affect anything on the script.

Here's my script (It's very long I know)

DO NOT USE THIS SCRIPT IN YOUR PROJECTS, IT IS OWNED BY ME AND ONLY ME

 using UnityEngine;
 using System.Collections;
 
 public class MainMenu : MonoBehaviour
 {
     private Menus currentMenu = Menus.Main;
     private bool canSwitch = false;
     public Vector2 scrollPosition;
 
     public GUISkin MySkin;
 
     private int buildingindex;
     private string buildingname;
     
     private float RenderSliderValue = 0.0F;
     private float ShadowSliderValue = 0.0F;
     private float TextureSliderValue = 0.0F;
     private float MasterVSliderValue = 0.0F;
 
     private bool VSync = false;
 
     //Controls
     private string ForwardText = "W";
     private string BackText = "S";
     private string LeftText = "A";
     private string RightText = "D";
     private string JumpText = "SPACE";
 
     enum Menus
     {
         Main,
         Options,
         Sound,
         MyGraphics,
         Credits,
         MyGUI,
         Controls,
     }
 
     void OnGUI()
     {    
         GUI.skin = MySkin;
         switch(currentMenu)
         {
             case Menus.Main:
                 Main();
             break;
 
             case Menus.Options:
                 Main();
                 Options();
             break;
                             
             case Menus.Sound:
                 Main();
                 Sound();
             break;
 
             case Menus.MyGraphics:
                 Main();
                 MyGraphics();
             break;
 
             case Menus.Credits:
                 Main();
                 Credits();
             break;
 
             case Menus.Controls:
                 Main();
                 Controls();
             break;
             }
     }
     
     //These are to control the main buttons on the menu
     
     void Main()
     {
         GUILayout.BeginArea(new Rect(Screen.width / 4, 0, 200, Screen.height));
         GUILayout.FlexibleSpace();
         GUILayout.BeginVertical();
         GUILayout.FlexibleSpace();
 
         GUILayout.Box("Main Menu");
         
         scrollPosition = GUILayout.BeginScrollView(scrollPosition, GUILayout.Width(200), GUILayout.Height(200));
         if(GUILayout.Button("New Game")){
             //Load New Game
         }
         if(GUILayout.Button("Load Game")){
             //Load Saved Scene Data
         }
         if(GUILayout.Button("Options")){
             currentMenu = Menus.Options;
         }
         if(GUILayout.Button("Credits")){
             currentMenu = Menus.Credits;
         }
         if(GUILayout.Button("Quit Game")){
             Application.Quit();
         }
         GUILayout.EndScrollView();
         GUILayout.FlexibleSpace();
         GUILayout.EndVertical();
         GUILayout.FlexibleSpace();
         GUILayout.EndArea();
     }
 
     void Options()
     {
             GUILayout.BeginArea(new Rect(Screen.width / 2, 0, 200, Screen.height));
             GUILayout.FlexibleSpace();
             GUILayout.BeginVertical();
             GUILayout.FlexibleSpace();
             
             GUILayout.Box("Options");
             
             scrollPosition = GUILayout.BeginScrollView(scrollPosition, GUILayout.Width(200), GUILayout.Height(200));
             if(GUILayout.Button("Graphics")){
             currentMenu = Menus.MyGraphics;
             }
             if(GUILayout.Button("Sound")){
             currentMenu = Menus.Sound;
             }
             if(GUILayout.Button("Controls")){
                 currentMenu = Menus.Controls;
             }
             GUILayout.EndScrollView();
             GUILayout.FlexibleSpace();
             GUILayout.EndVertical();
             GUILayout.FlexibleSpace();
             GUILayout.EndArea();
     }
 
     void Credits()
     {
             GUILayout.BeginArea(new Rect(Screen.width / 2, 0, 200, Screen.height));
             GUILayout.FlexibleSpace();
             GUILayout.BeginVertical();
             GUILayout.FlexibleSpace();
             
             GUILayout.Box("Credits");
             
             scrollPosition = GUILayout.BeginScrollView(scrollPosition, GUILayout.Width(200), GUILayout.Height(200));
             GUILayout.Label("Lead Developer: Daniel Knight");
             GUILayout.Label("Lead Programmer: Daniel Knight");
             GUILayout.Label("Lead Modeller: Teo Tuder");
             GUILayout.Label("Lead Developer: Daniel Knight");
             GUILayout.FlexibleSpace();
             GUILayout.Label("SPECIAL THANKS");
             GUILayout.Label("F33L!");
             GUILayout.Label("ThePenisBoy");
             GUILayout.Label("Nick");
             GUILayout.Label("Killerbill");
             GUILayout.Label("HailTheFail");
             GUILayout.Label("lateroflife");
             GUILayout.Label("Anttony Koibu");
             GUILayout.Label("Cornelius Kilegran");
             GUILayout.Label("Jack Mitchell");
             GUILayout.Label("Jack Skinner");
             GUILayout.Label("Ashwin Bali");
             GUILayout.Label("Ian Hell");
             GUILayout.Label("Peyton");
             GUILayout.Label("Sven Linnemann");
             GUILayout.Label("Teo Tudor");
             GUILayout.Label("Simon|Gagup|Skullbeat");
             GUILayout.Label("Tim cleall");
             GUILayout.Label("CalmCaterpillar");
 
             GUILayout.EndScrollView();
             GUILayout.FlexibleSpace();
             GUILayout.EndVertical();
             GUILayout.FlexibleSpace();
             GUILayout.EndArea();
     }
     void MyGraphics()
     {
             GUILayout.BeginArea(new Rect(Screen.width / 2, 0, 200, Screen.height));
             GUILayout.FlexibleSpace();
             GUILayout.BeginVertical();
             GUILayout.FlexibleSpace();
             
             GUILayout.Box("Graphics");
             
             scrollPosition = GUILayout.BeginScrollView(scrollPosition, GUILayout.Width(200), GUILayout.Height(200));
 
             GUILayout.Label("Render Distance");
             RenderSliderValue = GUILayout.HorizontalSlider(RenderSliderValue,0.0f,10.0f);
 
             GUILayout.Label("Shadow Distance");
             ShadowSliderValue = GUILayout.HorizontalSlider(ShadowSliderValue,0.0f,10.0f);
 
             if(GUILayout.Button("V-Sync On/Off"))
             {
                 if(VSync)
                 {
                     VSync = true;
                     QualitySettings.vSyncCount = 1;
                 }
                 else
                 {
                     VSync = true;
                     QualitySettings.vSyncCount = 0;
             }
 
             GUILayout.Label("Texture Quality");
             TextureSliderValue = GUILayout.HorizontalSlider(TextureSliderValue,0.0f,10.0f);
 
             GUILayout.EndScrollView();
             GUILayout.FlexibleSpace();
             GUILayout.EndVertical();
             GUILayout.FlexibleSpace();
             GUILayout.EndArea();
         }
     }
 
     void Controls()
     {
             GUILayout.BeginArea(new Rect(Screen.width / 2, 0, 200, Screen.height));
             GUILayout.FlexibleSpace();
             GUILayout.BeginVertical();
             GUILayout.FlexibleSpace();
             
             GUILayout.Box("Controls");
             
             scrollPosition = GUILayout.BeginScrollView(scrollPosition, GUILayout.Width(200), GUILayout.Height(200));
             
             GUILayout.Label("Forward");
             ForwardText = GUILayout.TextField(ForwardText.ToUpper(),10);
 
             GUILayout.Label("Back");
             BackText = GUILayout.TextField(BackText.ToUpper(),10);
 
             GUILayout.Label("Left");
             LeftText = GUILayout.TextField(LeftText.ToUpper(),10);
 
             GUILayout.Label("Right");
             RightText = GUILayout.TextField(RightText.ToUpper(),10);
 
             GUILayout.Label("Jump");
             JumpText = GUILayout.TextField(JumpText.ToUpper(),10);
             
             GUILayout.EndScrollView();
             GUILayout.FlexibleSpace();
             GUILayout.EndVertical();
             GUILayout.FlexibleSpace();
             GUILayout.EndArea();
     }
 
     void Sound()
     {
             GUILayout.BeginArea(new Rect(Screen.width / 2, 0, 200, Screen.height));
             GUILayout.FlexibleSpace();
             GUILayout.BeginVertical();
             GUILayout.FlexibleSpace();
             
             GUILayout.Box("Sound");
             
             scrollPosition = GUILayout.BeginScrollView(scrollPosition, GUILayout.Width(200), GUILayout.Height(200));
             
             if(GUILayout.Button("Sound On/Off"))
             {
                 if(AudioListener.volume != 0)
                 {
                     AudioListener.volume = 100;
                 }
                 else
                 {
                     AudioListener.volume = 0;
             }
 
             GUILayout.Label("Master Volume");
             MasterVSliderValue = GUILayout.HorizontalSlider(MasterVSliderValue,0.0f,10.0f);
 
             
             GUILayout.EndScrollView();
             GUILayout.FlexibleSpace();
             GUILayout.EndVertical();
             GUILayout.FlexibleSpace();
             GUILayout.EndArea();
         }
     }
 }

I know the buttons everything inside the script doesn't do anything as I have only just started with this script