click on GUI button goes through to a collider...

I show a menu when the player hits ESC with GUILayout stuff. Now when I hit my "Resume Game" button in that menu, the click seems to go right through the GUI and a collider behind it is triggered too.

To prevent this, I did this:

 void OnMouseUpAsButton () {
     if (GameGUI.menuDialog == false) {
         ReactOnClick ();
     }
 }

The GUILayout.button reacts only after the mouse is up again and then sets GameGUI.menuDialog = false (the menu sets it to true initially)

However the Collider still gets the click.

I even did:

 myTile.gameObject.renderer.enabled = false;
 myTile.gameObject.collider.enabled = false;
 

when the menu pops up, and:

 myTile.gameObject.renderer.enabled = true;
 myTile.gameObject.collider.enabled = true;

when it closes. But still the collider recieves the click.

I know this is a tricky one and the problem might even lie somewhere else, but I´m pretty clueless here right now. Perhaps someone had similar problem already and can give me a hint or so?