The popup when clicking an EditorGUI.EnumPopup inside a scaled GUI.matrix, is opened in the wrong location

Is there any solution for this other than rewriting the whole function yourself, with a modified positioning system?

As I could not find any real solution (and still seems to be an issue in ShaderForge ^^), here is a simple workaround:
Replace the EnumPopup by a button to trigger a GenericMenu when you click it, something like that:

using UnityEngine;
using UnityEditor;
using System.Collections;

public class FakeEnumPopup : EditorWindow 
    static void ShowEditor()
        FakeEnumPopup win = EditorWindow.GetWindow<FakeEnumPopup>();

    GenericMenu menuToShow;

    GenericMenu myPopup;
    string[]    myPopupList;
    int         myPopupSelectedID = 0;

    float zoom = 1f;

    void InitMenus()
        myPopupList = new string[]{"item1", "item2", "item3", "item4", "item5"};
        myPopup     = new GenericMenu();

        for (int i =0; i < myPopupList.Length; i++)
            myPopup.AddItem(new GUIContent(myPopupList*), false, MyPopupCallback, i);*


void MyPopupCallback(object obj)
myPopupSelectedID = (int)obj;
menuToShow = null;

void OnGUI()
zoom = GUILayout.HorizontalSlider(zoom, 0.1F, 10.0F);

// Initialize the generic menu(s) if it was not done yet
if(myPopupList == null)

// Mess with GUI.Matrix
Matrix4x4 previousMatrix = GUI.matrix;
GUIUtility.ScaleAroundPivot(new Vector2(zoom, zoom), new Vector2(Screen.width / 2, 16f));

GUILayout.Label(“some random content in the scaled area”);
GUILayout.Label(“and some more”);
// Call myPopup when the button is clicked
if (GUILayout.Button(myPopupList[myPopupSelectedID]))
menuToShow = myPopup;

// Restore GUI.Matrix
GUI.matrix = previousMatrix;

// Check if a menu has been called and show it
if (menuToShow != null)
menuToShow = null;